5. Coronavirus disease (COVID-19)

Key information

Mode of transmission

Aerosolised droplets.

Incubation period

Most commonly 2–5 days (range 1–14 days).

Period of communicability

From 1–2 days before, and typically transmissibility peaks 5 days after symptom onset. Asymptomatic spread is documented.

Incidence and burden of disease

Global pandemic ongoing.

The burden of disease predominantly lies with older adults, those with comorbidities and health care workers exposed to patients with high viral loads. Children generally experience milder disease.

Funded vaccines

mRNA-CV: Comirnaty (manufacturer Pfizer/BioNTech).

Adjuvanted rCV: Nuvaxovid (manufacturer Novavax).

Dose, presentation, route
(see sections 5.4.4 and 5.4.5

mRNA CV: Comirnaty

mRNA-CV (30 µg)

  • purple cap
  • 0.3 mL dose
  • multi-dose vial, to be diluted before use
  • intramuscular injection
  • Storage once thawed:
    • undiluted, +2° to 8°C expiry 1 month (31 days)
    • diluted (in vial or drawn up), +2° to 30°C expiry 6 hours

mRNA-CV (10 µg)

  • orange cap
  • 0.2 mL dose
  • Multi-dose vial, to be diluted before use
  • Intramuscular injection
  • Storage once thawed:
    • undiluted, +2° to 8°C expiry 10 weeks
    • diluted, in vial +2° to 8°C expiry 12 hours or drawn up +2° to 30°C expiry 6 hours

Adjuvanted rCV: Nuvaxovid

  • 0.5 mL dose
  • Blue cap
  • multi-dose vial, no dilution required
  • intramuscular injection
  • storage: +2° to 8°C (up to 6 months)
    • Use opened vial within 6 hours of first use, store at +2° to 8°C
    • drawn up vaccine within 6 hours (and before expiry)

Funded vaccine indications and schedule (see section 5.4.5)

mRNA-CV (30 µg)

  • Two doses, recommended to be given 6–8 weeks apart, can be given at least 21 days apart
  • For use from age 12 years
  • A third primary dose given at least 8 weeks after first two doses for those with severe immunocompromise from age 12 years (see section 5.5.9)
  • A booster dose given at least 3 calendar months to those aged 18 years or at least 6 months to those aged 16–17 years after completion of primary course (see section 5.5.11)
  • Certain individuals from age 16 years are recommended a second booster dose given at least 6 months after previous dose (see section 5.5.11)

mRNA-CV (10 µg)

  • Two doses recommended to be given at least 8 weeks apart, can be given at least 21 days apart
  • For use in children aged 5 to 11 years, inclusively
  • A third primary dose given at least 8 weeks after first two doses for those with severe immunocompromise from age 5 years (see section 5.5.9)

Other funded vaccine indication and schedule

Two doses of adjuvanted rCV, given at least 21 days apart for use from age 12 years

This vaccine can be used for a two-dose primary course without prescription. If this vaccine is used as second or third primary dose after mRNA-CV, a prescription is required. A prescription is not required for use of rCV as a booster dose from age 18 years.

Contraindications
(see section 5.6.1)

mRNA-CV and rCV: A history of anaphylaxis to any component or previous dose.

Precautions
(see section 5.6.2)

mRNA-CV and rCV: A definite history of anaphylaxis to any other product is a precaution not contraindication.

Defer further doses if individual develops myocarditis/pericarditis after any dose of mRNA-CV or rCV. Seek specialist immunisation advice regarding future COVID-19 vaccination doses.

Potential responses to vaccine
(see section 5.7.1)

mRNA and rCV: Generally mild or moderate: injection site pain, headache, fever, muscle aches, dizziness and nausea, a day or two after vaccination. These responses are more commonly reported after second dose and in younger adults (<55 years).

Vaccine effectiveness
(see section 5.4.3)

mRNA-CV (30 µg): Clinical trial data showed efficacy against confirmed symptomatic COVID-19 of 90–98% after two doses.

mRNA-CV (10 µg): Clinical trial data showed efficacy against confirmed, symptomatic COVID-19 of 68–98% after two doses in children aged 5-11 years.

rCV: Clinical trial data gave efficacy of 80–95% against symptomatic COVID-19.

Effectiveness of these vaccines is maintained against severe disease with recommended boosters but wanes for mild disease over a period of weeks after the primary course.

Public health measures

Ongoing testing for all suspected cases.
For current information refer to COVID-19 (novel coronavirus).

5.1. Virology

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a member of the Coronaviridae family and the Betacoronavirus genus. This enveloped, positive-strand RNA virus encodes four major structural proteins – spike (S), membrane (M), envelope (E) and a helical nucleocapsid (N). To enter host cells, the spike protein, which forms the characteristic crown-like (Latin: corona) surface structures, binds to the angiotensin-converting enzyme-2 (ACE2) receptor most frequently found on human respiratory tract epithelium.[1, 2] SARS-CoV-2 was first detected in late 2019 in China and is thought to be a zoonotic disease of an unidentified origin.

As with most RNA viruses, mutations occur and variant strains of SARS‑CoV‑2 have been identified that have increased transmissibility, altered virulence, or have reduced the effectiveness of public health measures. WHO has classified genetic variants into three classes: variants of concern, variants of interest and variants under monitoring.[3] Emergence of new variants is monitored in New Zealand by ESR through whole genome sequencing of specimens taken from hospitalised cases and wastewater sampling. For more information on COVID-19 variants see the Ministry of Health website.

5.2. Clinical features

Coronavirus disease 2019 (COVID‑19) is caused by the SARS-CoV-2 virus, which infects the respiratory tract and is transmitted human to human primarily through respiratory droplets and aerosols. Documented transmission has also occurred through direct contact and rarely fomites (objects or materials that can carry infection).

The symptoms of COVID‑19 range widely from asymptomatic or a mild respiratory tract infection to severe and pneumonia, which can lead to severe inflammatory disease and respiratory failure. The most common symptoms of COVID-19 are like those of other common respiratory illnesses and include a new or worsening dry cough, sneezing and rhinorrhoea or nasal congestion, fever, sore throat, shortness of breath and fatigue. Unlike other respiratory viral infections, COVID‑19 is frequently associated with a temporary loss of smell or altered sense of taste. Some cases have reported gastrointestinal symptoms including nausea, diarrhoea, vomiting and abdominal pain, headache, muscle aches, malaise, chest pain, joint pain, and confusion or irritability; these symptoms almost always occur with one or more of the common symptoms. For most cases COVID‑19 is a mild disease, but some can develop more severe disease or exacerbation of comorbidities. As for influenza and other respiratory viruses, some of those with laboratory-confirmed infection remain asymptomatic.

In the early stages, it is difficult to distinguish COVID 19 symptoms from other common viral infections. The most reliable common diagnostic test has been detection of viral mRNA from a nasopharyngeal swab, using PCR assay and rapid antigen tests (RATs).

The incubation period is typically around two to five days (up to 14 days). Individuals may be infectious from up to two days before becoming symptomatic, with infectiousness typically peaking within five days of symptom onset.[4] Unlike previous coronavirus outbreaks (SARS and MERS), transmission of SARS-CoV-2 can also occur before the onset of symptoms or from asymptomatic individuals.[5] Viral loads and infectiousness are highest immediately after symptom onset, and most transmission occurs in household settings.[6, 7]

It is currently unclear what or for how long protection is provided from previous infection with SARS-CoV-2. Neutralising antibodies have been detected and remained relatively stable between eight to 11 months after primary infection.[8, 9] Reinfection, including in vaccinated individuals, can occur and is likely due to being infected with different variants of SARS-CoV-2 or when neutralising antibody immunity has waned. The risk of reinfection has been shown to be reduced in vaccinated individuals and hybrid immunity, of infection and vaccine, reduces the risk of COVID-19 hospitalisation.[10, 11] This likely to be highly variable so continued COVID-19 vaccination post infection is recommended as per the Schedule.

5.2.1. Children and young adults

Commonly, children have mild or no symptoms of COVID-19 with a short duration of illness; symptoms typically include headache, fever, cough, and may include sore throat, nasal congestion, sneezing, muscle aches and fatigue.[12] Around one in five children with symptomatic COVID-19 present with gastrointestinal symptoms, such as nausea, vomiting, abdominal pain and diarrhoea.

The incidence of severe or fatal disease in children is significantly lower than in adults.[13] Children at higher risk of more severe disease are predominantly those living with pre-existing health conditions. These risk factors are prevalent in New Zealand children, particularly children of Māori and Pacific ethnicity.[14, 15] Pre-existing conditions associated with higher risk from COVID-19 in children include obesity, diabetes, asthma, cardiac and pulmonary diseases, immune disorders, metabolic disease, cancer, neurological, neurodevelopmental (in particular, Down syndrome [trisomy 21]) and neuromuscular conditions.[16, 17] A systematic review found children with comorbidities were 25 times more likely to have severe COVID-19 than those without (5.1 percent vs 0.2 percent) and have a 2.8 times higher relative risk of death.[17] Children who develop pulmonary complications (eg, pneumonia) have a similar progression of disease as seen in adults, requiring oxygenation in hospital and in some cases corticosteroids treatments.[18]

5.2.2. Risk groups

Risk factors for severe disease include older age, male, smoking,[19] obesity and chronic medical conditions, including diabetes,[20] cancer, chronic respiratory disease, cardiovascular disease, chronic kidney disease, hypertension, immunocompromise[21] and pregnancy (see below). Increased incidence is well documented in some ethnic groups but seems primarily related to prevalence of the risk factors listed above. Increasing age is the most important risk factor for severe disease, due to declining immune function and high prevalence of comorbidities. The highest risk group for severe illness and mortality is those aged over 70 years, although Māori and Pacific populations experience age-related risk at a younger age.

Health care workers

Patient-facing health care workers caring for patients with COVID‑19 are likely to be exposed to higher viral loads, placing them and their household members at greater risk of developing COVID‑19 than the general population.[22] However, the use of personal protective equipment (PPE) and other measures aimed at reducing nosocomial viral transmission have been shown to be effective, such that, when COVID‑19 is prevalent in the community, health care workers are more likely to catch COVID‑19 from an infected household member.[7]

Pregnancy

Pregnancy is not associated with increased risk of being infected with SARS-CoV-2, but it can increase the risk of severe disease and death compared with age-matched non-pregnant women.[23, 24, 25, 26] While the absolute risk of severe outcomes during pregnancy is low compared with absolute risk due to advanced age, the risk of hospital admissions is three times higher and the rate of ICU care for COVID‑19 has been found to be five times higher (relative risk 5.04; 95% CI 3.13–8.10) for pregnant women than for non-pregnant women.[25] Obesity, hypertension, asthma, autoimmune disease, diabetes and older age are also associated with severe COVID‑19 in pregnancy and postpartum.[27]

Infants born to those with COVID‑19 are at increased risk of preterm birth, particularly due to early delivery, and neonatal ICU admission.[24, 27] Early studies do not suggest intrauterine transmission, but transmission during birth has been shown in around 3 percent of neonates.[28] Most neonatal infections are asymptomatic or mild, but around 12 percent experience severe disease with dyspnoea and fever as the most commonly reported signs.[29]

5.2.3. Post-infection complications

Post-acute COVID-19 sequalae or commonly called ‘long COVID’ is characterised by persistent symptoms lasting for more than three months and appears to affect around 10 percent of those infected, particularly those with at least five symptoms in the first week of illness.[30, 31, 32] Post-acute manifestations include cardiovascular, pulmonary and neurological effects, including chronic fatigue, dyspnoea, specific organ dysfunction and depression.[33]

Long COVID-19 is not well described in children but appears to be less common, particularly under the age of 12 years, than in adults.[18, 34, 35, 36]

For further information see the Ministry of Health Long COVID-19 website.

Paediatric multisystem inflammatory syndrome

Paediatric multisystem inflammatory syndrome temporally associated with SARS-CoV-2 (PIMS-TS or MIS-C) is a rare, delayed complication of COVID-19 following largely asymptomatic SARS-CoV-2 infection in children and adolescents.[37, 38] PIMS-TS can occur approximately one month after symptomatic or asymptomatic SARS-CoV-2 infection affecting different parts of the body and usually presents as a fever, rash and abdominal pain, although in more severe cases, myocarditis and low blood pressure can occur.[39] Early diagnosis and appropriate treatment improve outcomes. Data from the US has shown that the risk PIMS-TS is highest in marginalised and ethnic minority groups.[40] The PAEDS network in Australian found that there was a lower risk for PIMS-TS in children when infected with the omicron variant, from a rate of 13 (95% CI 4-29) cases per 100,000 during the pre-delta period (March 2020 to May 2021) to 5 (4-7) per 100,000 during the delta period (June to December 2021) and 0.8 (0-1) per 100,000 during the omicron period to January 2022 to April 2022.[41]

5.3. Epidemiology

5.3.1. Global burden of disease

SARS-CoV-2 was first identified in January 2020 following clusters of distinctive pneumonia cases were observed in Wuhan, China during December 2019. This virus has genetic and clinical similarity to the coronavirus causing the severe acute respiratory syndrome (SARS) epidemic from 2002 to 2004. A public health emergency of international concern (PHEIC) was announced in late January 2020. By the time the COVID‑19 pandemic was declared by the World Health Organization (WHO) on 11 March 2020, there were 118,000 reported COVID‑19 cases and 4,291 associated deaths in 114 countries. The global death toll surpassed one million by late September 2020. Case numbers and death continued to increase, with a rapid peak in cases at the end of December 2021 due to the more infectious omicron variant. As of 8 November 2022, WHO reported over 6.5 million cumulative COVID-19 deaths.

See the WHO Coronavirus Disease (COVID‑19) Dashboard for the latest official data. Actual rates are expected to be considerably higher than officially reported rates, especially since milder infections may not be reported.

The infection-fatality rate, while still high particularly in the older age groups, has reduced since the start of the pandemic, partly due to changes in the prevalent variants but also due to public health measures that include vaccination, improved clinical recognition and management and the use of therapies of demonstrated value, such as dexamethasone and antiviral medications such as nirmatrelvir and ritonavir and molnupiravir.

The use of vaccines has reduced the global burden of COVID‑19 significantly. The first phase I clinical trial for a COVID‑19 vaccine commenced in March 2020 and the first public vaccination dose was administered in the United Kingdom on 8 December 2020. By late 2022, 11 COVID-19 vaccines had been granted emergency use listing or approval by the WHO.

5.3.2. New Zealand epidemiology

The first case of COVID‑19 was reported in New Zealand on 28 February 2020. Border restrictions were implemented on 16 March 2020 as cases numbers increased and clusters of transmission were identified. On 25 March 2020, New Zealand entered a nationwide lockdown (‘Alert level four’). With rapid contact tracing and the public health COVID-19 protection framework, the spread of SARS-CoV-2 was restricted during 2020 and 2021. Only 19 percent of the introductions of virus in 2020 resulted in ongoing transmission or more than one additional case.[42] Prior to the outbreak of the Delta variant in August 2021, most of the reported cases during 2021 were imported from overseas (over 95 percent from 1 January to 9 August 2021).

From 16 August 2021, the number of cases in New Zealand began to increase sharply due initially to the highly infectious Delta variant. From January 2022, when the more infectious Omicron variant entered the community, case numbers rose sharply but at this stage around 90 percent of the population aged from 12 years had been vaccinated with at least two doses of COVID-19 vaccine. As of 7 November 2022, there were over 1.87 million cases, over 20,000 hospitalisations, and 534 ICU admissions for COVID-19. There were 1,347 deaths coded with COVID-19 as the underlying cause, and the vast majority (92 percent) were aged over 59 years.

The COVID-19 Mortality Report in published September 2022 found that although COVID-19-attributed mortality was highest in older age groups, based on age-adjusted estimates, the risk of mortality for those aged under 60 years was 3.7 times higher for those Māori and 3.9 times higher for those of Pacific ethnicities than of European and Other ethnicities.[43] Comorbidity in those under the age of 60 years significantly increased the risk of mortality by 78 times, and explained 59 percent of the increased risk for Māori and 69 percent for Pacific ethnicities. Vaccination was shown to have a strong protective effect: after adjusting for age, sex, comorbidities and vaccination status (>2 doses), mortality risk was lowered but still 1.7 times higher in Māori and 1.9 times higher for Pacific compared with European/Other ethnicities.[43]

For current details on case demographics see COVID-19: Data and statistics and for the mortality report see COVID-19 Mortality in Aotearoa New Zealand: Inequities in Risk.

5.4. Vaccines

5.4.1. Introduction

Clinical trials for COVID‑19 vaccine candidates began shortly after the pandemic was announced in March 2020. Between October to December 2020, the New Zealand Government signed advanced purchase agreements for four vaccine candidates, with purchase dependent on approval for use from the New Zealand Medicines and Medical Devices Safety Authority (Medsafe). This is an ongoing process and, therefore, the availability and eligibility for these different vaccines may change.

5.4.2. Available vaccines

Vaccines for COVID 19 continue to undergo phase III clinical trials, and the Medsafe review process is ongoing for each vaccine candidate examining clinical trial and post-marketing surveillance data. The first vaccine to receive approval for use in New Zealand was an mRNA-based COVID 19 vaccine (mRNA-CV, trade name Comirnaty) manufactured by Pfizer/BioNTech. Provisional consent approval was granted on 3 February 2021. Two adenoviral vector COVID-19 vaccines were granted provisional approval in July 2021: Vaxzevria (manufactured by AstraZeneca) and COVID-19 Vaccine Janssen. On 4 February 2022, provisional approval was granted to an adjuvanted recombinant spike protein subunit COVID-19 vaccine (rCV; trade name Nuvaxovid) manufactured by Serum Institute of India on behalf of Novavax and sponsored in New Zealand by Biocelect (available from March 2022).

Provisional consent imposes conditions on these vaccines to restrict their use by health professionals according to the available data at time of approval. This approval status allows New Zealanders early access to medicines with significant unmet clinical need under the Medicines Act.

Funded vaccines

The mRNA-CV, Comirnaty, consists of messenger ribonucleic acid (mRNA) encoding the full-length spike glycoprotein of the SARS-CoV-2 virus inside a lipid nanoparticle (named tozinameran). The spike protein has an adjuvant effect, so no additional adjuvant is included. It is designated BNT162b2 in clinical trials conducted by Pfizer and BioNTech. This mRNA vaccine delivers the instructions for human cells to build the viral antigen, SARS-CoV-2 spike protein. The mRNA is temporarily protected from degradation by the lipid nanoparticle that also facilitates fusion with the recipient’s cell wall.[44, 45]

The adjuvanted recombinant COVID-19 vaccine (abbreviation rCV), Nuvaxovid, contains recombinant SARS-CoV-2 spike protein in a stabilised prefusion conformation. The spike protein is produced by an insect cell-line that has been infected with an insect baculovirus expressing SARS-CoV-2 spike protein genes. Together, the purified spike proteins and the adjuvant matrix are formed into immunogenic nanoparticles. The proprietary adjuvant (Matrix-M) contains two purified saponin fractions from Quillaja saponaria (soapbark tree) which enhances the innate immune response and activates the production of neutralising antibodies and T and B cell immunity. The vaccine was designated NVX-2373 in clinical trials conducted by Novavax and is sponsored in New Zealand by Biocelect.

mRNA-CV – Comirnaty (Pfizer/BioNtech)
mRNA-CV (30 µg) for ages from 12 years (purple cap)

Each 0.3 mL dose of mRNA-CV contains:

  • 30 µg of tozinameran, a single-stranded 5’-capped mRNA encoding pre-fusion stabilised SARS-CoV-2 full-length spike glycoprotein embedded in a lipid nanoparticle. The mRNA is produced using cell-free in vitro transcription from DNA templates.
  • The lipid nanoparticle contains ALC-0315 ((4‑hydroxybutyl)azanediyl)bis(hexane-6,1-diyl)bis(2-hexyldecanoate)), ALC‑0159 (2-[(polyethylene glycol)-2000]-N,N-ditetradecylacetamide), distearoylphosphatidylcholine (DSPC)) and cholesterol.
  • Also contains potassium chloride, monobasic potassium phosphate, sodium chloride, dibasic sodium phosphate dihydrate, sucrose and water for injection.
mRNA-CV (10 µg) for children aged 5 to 11 years (orange cap)

Each 0.2 mL dose contains:

  • 10 µg of tozinameran, a single-stranded 5’-capped mRNA encoding pre-fusion stabilised SARS-CoV-2 full-length spike glycoprotein embedded in a lipid nanoparticle. The mRNA is produced using cell-free in vitro transcription from DNA templates.
  • The lipid nanoparticle contains ALC-0315 ((4 hydroxybutyl)azanediyl)bis(hexane-6,1-diyl)bis(2-hexyldecanoate)), ALC 0159 (2-[(polyethylene glycol)-2000]-N,N-ditetradecylacetamide), distearoylphosphatidylcholine (DSPC)) and cholesterol.
  • Also contains Tris/sucrose buffer: tromethamine (also known as Tris), tromethamine hydrochloride, sucrose and water for injection

The 10 µg paediatric formulation of mRNA-CV (with orange cap) uses a Tris/sucrose buffer to improve the stability at +2° to 8°C.

Adjuvanted rCV – Nuvaxovid (Novavax)

Each 0.5 mL dose of adjuvanted rCV contains:

  • 5 µg of recombinant SARS-CoV-2 spike protein (produced in insect cell line, Sf9)
  • 50 µg adjuvant Matrix M - fraction A and fraction C saponins from Quillaja saponaria formed into lipid nanoparticles containing cholesterol, phosphatidyl choline, monobasic potassium phosphate and potassium chloride
  • Also contains: dibasic sodium phosphate heptahydrate, monobasic sodium phosphate monohydrate, sodium chloride, polysorbate 80, sodium hydroxide (for adjustment of pH), hydrochloric acid (for adjustment of pH) and water for injections

Other vaccines

An adenoviral vector COVID-19 vaccine, Vaxzevria (abbreviation ChAd-CV), was provisionally approved for use in New Zealand on 29 July 2021. This vaccine, based on a recombinant non-replicating chimpanzee adenovirus ChAdOx1-S, contains a transgene encoding the prefusion SARS-CoV-2 spike glycoprotein. The adenovirus delivers the instructions to make replicas of the SARS-CoV-2 viral protein. It has been modified to be unable to replicate and only the gene encoding the spike protein (the antigen) can be expressed. The virus is destroyed once the protein instructions have been delivered. This vaccine is manufactured by AstraZeneca (clinical trial designation AZD122). This vaccine was used from late November 2021 to September 2022. It is no longer available in New Zealand.

Another adenoviral vector COVID-19 vaccine (Ad26.COV2.S, brand names Jcovden or COVID-19 Vaccine Janssen) was approved for use in New Zealand on 7 July 2021. Using a similar platform to ChAd-CV, this vaccine (abbreviated here to Ad26-CV) contains a modified non-replicating human adenovirus, Ad26, that carries a transgene coding for the COVID-19 prefusion SARS-CoV-2 spike protein. This vaccine is not available in New Zealand.

5.4.3. Efficacy and effectiveness

mRNA COVID 19 vaccine – Comirnaty (Pfizer/BioNTech)

Immunogenicity

Before the phase III efficacy studies were conducted, immunogenicity was a key indicator in the early-phase clinical trials of COVID‑19 vaccines in 2020. Virus neutralising antibody responses measured the killing of live SARS-CoV-2 and/or pseudovirus in cell culture, and humoral responses were compared with human convalescent sera collected from patients who had recovered from COVID‑19. The initial phase I and II clinical trials evaluated two vaccine candidates (BNT162b1 and BNT162b2) in adults. Both induced dose-dependent neutralising antibody titres similar or higher to the titres in convalescent sera.[46] The antibody response was lower in older people (aged 55–85 years) than in younger people (aged 18–55 years), but both groups had higher average neutralising antibody levels than those who had SARS-CoV-2 infection.

Similar immunogenicity was shown in a phase III trial in participants aged 12–15 years and those aged 16–25 years given 30 µg dose of mRNA-CV, with the neutralising antibody responses higher in the younger adolescents (geometric mean ratio 1.76; 95% CI 1.47–2.10).[47] In 264 children aged 5–11 year, a phase II/III clinical trial found that the immunogenicity of 10 µg doses of mRNA-CV was similar to that seen in young people aged 16–25 years given 30 µg doses.[74] At one month after two doses given 21 days apart, the neutralising antibody geometric mean ratio was 1.04 (0.93–1.18) between the children and young adults.

Efficacy – clinical trial data

Efficacy of 30 µg mRNA-CV (BNT162b2) was assessed in the phase III component of a large, ongoing clinical trial in which 43,448 participants aged 16–85 years across six countries were randomised to receive vaccine or saline placebo, with two doses given 21 days apart.[49] Interim data, based on the early SARS-CoV-2 variants, indicated:

  • vaccine efficacy (VE) against symptomatic PCR-confirmed COVID‑19 was 94.8 percent (95% CI: 89.8–97.6 percent)
  • evidence of previous SARS-CoV-2 infection did not alter this efficacy (VE 95.0 percent without and 94.6 percent with and without previous infection)
  • similar efficacy (90–100 percent) was observed across all subgroups as defined by age, sex, race, ethnicity, baseline body-mass index (35 percent of participants were obese, BMI ≥ 30) and the presence of at least one co-existing medical condition (in 21 percent of participants)
  • moderate protection against COVID‑19 was observed before the second dose.[49]

For adolescents aged 12-15 years, observed vaccine efficacy for mRNA-CV (30 µg) in a 2020/21 phase III clinical trial was 100 percent (95% CI 75.3–100) against symptomatic COVID-19. A total of 2,220 randomised participants received two doses of vaccine or saline placebo given 21 days (19–42 days) apart. No cases of severe COVID-19 were observed in this age group.[47]

In children aged 5–11 years, vaccine efficacy of 90.7 percent (95% CI 67.798.3) against symptomatic COVID-19 was seen from seven days after dose two in 1,305 children (without evidence of previous infection) who received mRNA-CV (10 µg) when compared with 663 who received placebo in the phase II/III clinical trial.[48]

Effectiveness of primary course – real-world experience

Early data from Israel at the start of its national COVID-19 immunisation programme, which included around 1.2 million vaccinated and unvaccinated individuals aged from 16 years, demonstrated that mRNA-CV was highly effective at preventing COVID-19 and severe disease, and these data were in line with those observed during clinical trials.[50] At the start of the programme in the UK in older adults, a significant reduction in symptomatic COVID-19 cases aged from 70 years was seen for at least six weeks after a single dose of mRNA-CV, with effectiveness of 70 percent (95% CI 59–78 percent) by days 28–34, plateauing to 61 percent (51–69 percent). Additionally, those that had been vaccinated were 43 percent (33–52 percent) less likely to require emergency hospitalisation and at 51 percent (37–62 percent) lower risk of death. At day 14 after a second dose (given 12 weeks after dose one), vaccine effectiveness reached 89 percent (85–93 percent).[51]

Effectiveness of mRNA-CV against symptomatic COVID-19 caused by the Delta variant was reduced in comparison with previous variants (ranging from around 78–93 percent),[52] but the vaccine remained highly effective against hospitalisation (73–94 percent), severe disease and death (80-97 percent) in a range of groups.[53] The risk of infection with Delta was also significantly lower in fully vaccinated compared with unvaccinated individuals (hazard ratio 0.35; 95% CI 0.32–0.39).[54]

Effectiveness of the two-dose primary course against Omicron variant was found to wane rapidly and booster doses were required to prevent symptomatic infection (see below).

Effectiveness against transmission

Effectiveness of mRNA-CV against transmission of SARS-CoV-2 is unclear and likely to depend on a range of factors, including rate of viral growth once infected and the infectivity of variant of the virus. It was expected the spread of the virus would decrease as the number of people who were vaccinated increased. During the Delta wave, evidence from the UK showed that vaccination against COVID-19 reduced the risk of infection and accelerated the viral clearance. Although peak viral loads were similar between infected vaccinated and unvaccinated individuals, the secondary attack rate between household contacts was 25 percent (95% CI 18–33 percent) in fully vaccinated individuals compared with 38 percent (24–53 percent) in unvaccinated individuals.[55] Transmission to non-immune individuals in households in Sweden was shown to be significantly reduced and correlated with the proportion of family members vaccinated.[56] The ability of the vaccine to prevent infection and transmission was further reduced with the emergence of the Omicron variants.

Effectiveness in adolescents and children

Interim effectiveness against Delta variant SARS-CoV-2 infection, irrespective of symptoms, was estimated to be 92 percent (95% CI 79–97) in adolescents aged 12-17 years in Arizona.[57] A test-negative case-control study in the US showed vaccination with mRNA-CV (30 µg) to be protective against PIMS-TS in adolescents aged 12–18, with an estimated effectiveness of 91 percent (95% CI 78–97 percent), a median of 84 days (range 52–122) after vaccine dose two.[58]

Vaccination with mRNA-CV in pregnancy reduces the risk of severe COVID-19 and provides passive immunity to the infant for the first few months of life.[59, 60, 61]

Adjuvanted recombinant COVID-19 vaccine – Nuvaxovid (Novavax)

Immunogenicity

Two doses of adjuvanted rCV were immunogenic in adults aged 18–59 years and 60–84 years. At 14 days after two doses given 21 days apart, neutralising antibody levels in both groups were higher than those in a panel of convalescent sera and all participants who received rCV seroconverted. At total of 1,283 participants were randomised 1:1:1:1 to receive one or two doses of vaccine (5 µg spike protein), a higher dose (25 µg) or placebo, and were stratified by age in the US and Australia. Both age groups had robust immune responses, although the older participants had lower antibody titres of anti-spike protein IgG or wild-type neutralising antibody than the younger group.[62]

Coadministration with influenza vaccines

Coadministration with influenza vaccine was investigated in a small phase I/II sub-study in UK hospitals. Around 400 participants were randomised to receive rCV and inactivated quadrivalent influenza vaccine for those aged 18–64 years or adjuvanted trivalent influenza vaccine for those aged 65 years or over, or rCV alone. Immunogenicity showed no change in the response to influenza vaccine but a reduction in antibody response to SARS-CoV-2. There was no difference in the seroconversion rates. Although the anti-spike protein IgG responses were 0.6-fold lower in the groups that received both vaccines, when post-hoc analysis of efficacy was considered, this reduction was not suggested to be clinically meaningful and in the younger age group, the anti-spike antibody levels were three-fold greater than found in convalescent serum.[63]

Efficacy – clinical trial

Data from two phase III clinical trials of adjuvanted rCV gave overall vaccine efficacy of 90 percent (95% CI 82.9-94.6 in PREVENT-19 study in US/Mexico and 80.2-94.6 percent in UK trial) against symptomatic COVID-19 from at least seven days after dose two.[64, 65] By age group, in approximately 10,000 vaccinated and placebo participants in the UK (randomised 1:1), vaccine efficacy against COVID-19 in those aged 18-64 years was 89.8 percent (79.7-95.5) versus 88.9 percent (20.2-99.7) in approximately 4,000 participants aged 65– 84 years[65] In a subgroup of approximately 6,000 participants with coexisting illness, vaccine efficacy was 90.9 (70.4-97.2)[65] These clinical trials were conducted during early 2021, against predominantly Alpha not Delta or Omicron variants.

Effectiveness – real-world

This vaccine has only been recently approved for use and real-world effectiveness is beginning to be evaluated. There is no published effectiveness data to date.

Duration of immunity

Especially with the emergence of more infectious variants, there has been insufficient time since the commencement of clinical trials and vaccination campaigns to assess fully how long-lived immunity lasts following immunisation or natural infection. A decline in vaccine efficacy was observed against SARS-CoV-2 infection and mild disease, particularly with emerging variants such as Delta and Omicron, but protection against severe disease has been maintained and enhanced with the use of booster doses. Waning in neutralising antibody levels has been correlated with predominantly mild or asymptomatic breakthrough infections in health care workers.[66] The greatest waning was observed in those aged over 65 years and those aged 40–64 years with underlying medical conditions compared with healthy adults.[67] Data indicated that vaccine effectiveness with the primary course against symptomatic infection caused by Omicron variant declines more rapidly than was seen against Delta.[68]

Although neutralising antibody levels wane,[69] and lower levels are less effective against the emerging variants such as Omicron, T cell responses and memory are maintained in vaccine recipients (for mRNA-CV and rCV).[70, 71]

Booster doses

To prolong protection many countries introduced a booster dose after the primary course. Booster dose programmes were accelerated following the emergence of the Omicron variant from late 2021, including in New Zealand.

mRNA COVID-19 vaccine

Booster doses, given from five months after the primary course, were shown to reduce the rates of symptomatic COVID-19 by a factor of 11.3 (95% CI 10.4–12.3) and severe illness by a factor of 5.4 (4.8–6.1) in older adults aged from 60 years in Israel.[72] The UK Health Security Agency reported that vaccine effectiveness against symptomatic infection was significantly lower against Omicron than Delta variant, such that by 15 weeks vaccine effectiveness had declined to between 34­–37 percent after two doses of mRNA-CV. At more than 25 weeks after two primary doses, mRNA-CV vaccine effectiveness was 25–35 percent against hospitalisations due to Omicron variant. From two weeks after a booster dose of mRNA-CV (30µg) given from 25 weeks after the primary course, effectiveness against mild infection was increased to 70–75 percent: 75.5 percent (95% CI 56–86) in those mRNA-CV primed and 71 percent (42–86) in those primed with ChAd-CV.[68] A booster with mRNA-CV increased effectiveness against hospitalisation to over 90 percent within two weeks but then declined to 75 percent after 10–14 weeks.[73]

These findings were supported by data from Canada, which showed vaccine effectiveness waned more rapidly after the primary series against symptomatic infection with Omicron compared with Delta variant. Vaccine effectiveness was significantly improved against symptomatic infection with Omicron variants, from <1% (-8 to 10 percent) to 61 percent (56–65 percent), by a booster dose of an mRNA COVID-19 vaccine given from 240 days after the second dose of primary course (with at least one dose of an mRNA vaccine). The booster dose was highly effective against severe outcomes of Delta or Omicron (98–99 percent and 87–98 percent, respectively).[74]

Second booster doses (ie, fourth doses) are recommended for certain groups. Fourth doses boosted both humoral and cellular immunity when given approximately seven months after a third dose booster in the UK. Anti-spike protein IgG titres were higher 14 days after a fourth dose than seen 28 days following the third dose (11–20 fold increase from day 0 to day 14 post fourth dose).[75] In an Israeli study, a fourth dose of mRNA-CV, given at least four months after the third dose to adults aged from 60 years, provided additional protection for at least six weeks and reduced the rate of severe COVID-19 by a factor of 3.5 (95% CI 2.7-4.6) compared with those who had received three doses, and reduced the rate of confirmed SARS-CoV-2 infection by a factor of two (1.0 –2.1) at four weeks. The study included over 1.2 million participants (1:1 received fourth and third doses).[76] There is marginal evidence that a fourth dose prevents infection in health care workers (given 4 months after dose three) – data from an open-label nonrandomised clinical trial in Israel, gave vaccine efficacy of 30 percent (-9 to 55) against Omicron infection and estimated 43 percent against symptomatic illness. Those who were infected were shown to have relatively high viral loads and likely to be infectious.[77]

Adjuvanted recombinant COVID-19 vaccine

Immunogenicity of homologous booster doses of rCV, evaluated during a secondary analysis of a phase II clinical trial, showed that antibody levels induced by the booster dose in healthy adults were higher than levels associated with efficacy in the primary response phase III trials.[69] In the phase II clinical trial, conducted in the US and Australia, a single booster dose was given approximately six months after two-dose primary course of rCV to 105 healthy adults aged 18 to 84 years. Immune responses at 28 days post booster (day 217) were compared with those at 14 days post dose two (day 35). Serum IgG GMTs increased 4.7-fold from day 35 to day 217 against ancestral SARS-CoV-2, and 4.1-fold in the neutralisation assay. Increases in functional ACE2 receptor binding inhibition were also observed from day 189 to day 217 (pre and post booster) against various variants, including a 24-fold increase against Delta and 20-fold increase against Omicron. Anti-spike IgG activity also showed improved titres against a range of variants, including 92.5-fold increase against Delta and 73.5-fold increase against Omicron.[69]

Mixed COVID-19 vaccine schedules

Heterologous priming

Much of the evidence available around mixed (heterologous) COVID-19 vaccine schedules investigated ChAd-CV (Vaxzevria) followed by mRNA-CV (Comirnaty) as the second dose (heterologous prime-prime schedules) in 2021.[78, 79] The humoral immune response was shown to be stronger with a ChAd/mRNA primary schedule than homologous ChAd-CV schedule against different SARS-CoV-2 variants including Delta.[78, 80] The T cell response was also found to be higher following heterologous dosing.[81] The ComCOV study in the UK found that when ChAd-CV was given 4 weeks after mRNA-CV, the anti-S protein IgG antibody response was lower than homologous mRNA-CV dosing (geometric mean ratio [GMR] 0.51; 95% CI 0.43–∞), but higher than ChAd/ChAd. Giving mRNA-CV after ChAd-CV first dose, produced a higher response than ChAd/ChAd dosing (GMR 9.2; 7.5–∞). Taking age, comorbidity and different immunological outcomes into consideration, the overall humoral response of mRNA/mRNA was favoured over mRNA/ChAd dosing and ChAd/mRNA was favoured over ChAd/ChAd.[82]

A phase II clinical trial (ComCOV 2) conducted in the UK investigated the safety and immunogenicity of mixed priming schedules with rCV. Between April and May 2021, 1,072 participants aged 50–78 years received a second dose of one of three COVID-19 vaccines a median of 9.4 weeks after receipt of a single dose of ChAd-CV or mRNA-CV.[83] Although when rCV was given as the second dose the antibody response was inferior to a second dose of mRNA-CV (GMR 0.5; 95% CI 0.4 to 0.7), rCV induced an 18-fold rise in anti-spike antibody concentration 28 days after vaccination, which were high than ChAd-CV. For those who received a first dose of ChAd-CV, a second dose with rCV antibody concentration was non-inferior to a second dose of ChAd-CV (GMR 2.8; 2.2 to 3.4).[83]

Heterologous boosting

As part of the UK COV-BOOST study, all vaccines used as third-dose boosters demonstrated superior immunogenicity compared with control (except an inactivated virus COVID-19 vaccine in mRNA-CV primed group) as measured by anti-spike IgG and neutralising assays.[84] Participants aged 30 years or over with no history of laboratory-confirmed SARS-CoV-2 infection were given a booster dose at least 84 days post two doses of mRNA-CV (30µg Comirnaty) or at least 70 days post two doses of ChAd-CV. Participants received one of six vaccines including rCV, half dose rCV, ChAd-CV, mRNA-CV (Comirnaty), mRNA-CV (Spikevax) or MenACWY as control. Cellular responses in ChAd-CV primed individuals were better boosted by rCV than in those primed with mRNA-CV. Optimal timing of the dosing intervals remains unclear.[84]

5.4.4. Transport, storage and handling

mRNA COVID 19 vaccine – Comirnaty (Pfizer/BioNTech)

mRNA-CV (30 µg) for ages 12 years and over

To preserve the integrity of the mRNA in this vaccine, storage at ultra-low temperature freezer (between -90°C and -60°C) is required. At these ultra-low temperatures, the shelf-life is 15 months. Trays of unopened vials may be stored and transported at -25°C to -15°C for a total of two weeks on one occasion only. Once an individual vial has been removed from the vial tray, it should be thawed for use.

The vaccine will be thawed in batches, packed into cartons and distributed from the central warehouse. Each carton will have a label with an updated batch number and expiry date and time. Expiry reduces from 15 months to 31 days once thawed. Thawed vaccines will be shipped to vaccination sites as per the standard cold chain distribution process.

Store undiluted vials (with purple cap) at +2°C to +8°C for up to 31 days (including up to 48 hours for transportation) including up to two hours at room temperature (up to +30°C). After dilution, store vials between +2°C and +30°C and use within six hours. Any remaining vaccine in the vial must be discarded after six hours. Do not refreeze. See 2021 Addendum to the National Standards for Vaccine Storage and Transportation for Immunisation Providers 2017 (2nd edition). See also ‘Guidance supporting the administration of mRNA-CV vaccine’ factsheet available from the COVID-19 Education website.

mRNA-CV (10 µg) for ages 5–11 years

This vaccine requires storage at ultra-low temperatures (-90°C to -60°C) and at this temperature has a shelf-life of 12 months. Store unopened, undiluted vials (with orange cap) at at +2°C to 8°C for up to 10 weeks within the 12 months shelf-life. Do not freeze. Transport according to the National Standards for Vaccine Storage and Transportation for Immunisation Providers 2017 (2nd edition).

Store diluted vaccine in vials at +2°C to 8°C for a maximum of 12 hours, or store vaccine drawn-up in syringe for a maximum of six hours at +2°C to 30°C. Prior to use, once an undiluted vial is taken out of the refrigerator, allow time (up to 2 hours) for the vaccine to reach room temperature and to be diluted. Discard any vaccine exceeding these times, accordingly. See also the IMAC COVID-19 Education factsheet ‘Paediatric Pfizer/BioNTech mRNA-CV 10µg Vaccine Preparation’ available from the COVID-19 Education website.

Adjuvanted recombinant COVID-19 vaccine – Nuvaxovid (Novavax)

Transport and store according to the National Standards for Vaccine Storage and Transportation for Immunisation Providers 2017 (2nd edition).

Store at +2°C to +8°C. Do not freeze. Protect vials from light. Unopened vials (with blue cap) have a shelf-life of up to six months. Opened vials should be used within six hours of first use. Vaccines should ideally be used within an hour of being drawn up. The maximum time the vaccine can be stored in a syringe is six hours when stored at +2°C to 25°C, and before the vial six-hour expiry is reached, whichever is soonest. To ensure optimum use, in New Zealand, the vaccine is recommended to be always stored in the fridge and, where practical, doses are drawn up as required.

See also the IMAC COVID-19 education factsheet, ‘Guidance for Nuvaxovid (Novavax) COVID-19 Vaccine Preparation’ available from the COVID-19 Education website.

5.4.5. Dosage and administration

mRNA COVID‑19 vaccine – Comirnaty (Pfizer/BioNTech)

mRNA-CV (30 µg) for ages from 12 years

Each dose of mRNA-CV is 0.3 mL (30 µg) to be administered intramuscularly. Two doses are given at least 21 days apart for individuals aged 12 years or older. All individuals from the age of 12 years are recommended to receive two doses of mRNA-CV (30 µg) given from eight weeks apart.

Each multi-dose vial (with purple cap) contains 0.45 mL of vaccine and should be diluted with 1.8 mL of 0.9% NaCl. Once diluted, each reconstituted vaccine will supply six (up to seven) doses of 0.3 mL. If the amount of vaccine remaining in the vial cannot provide a full 0.3 mL dose, discard the vial and any excess volume. Do not pool excess vaccine from multiple vials.

An observation period following vaccination of at least 15 minutes is recommended (see section ‎5.6.2). This is to ensure that any anaphylactic-type reactions can receive prompt treatment.

This vaccine is latex-free. The vial stopper is made with synthetic rubber (bromobutyl), not natural rubber latex.

mRNA-CV (10 µg) for ages 5 to 11 years

Each 0.2 ml dose (10 µg) is to be administered intramusclarly. Two doses are given at least 21 days apart for individuals aged 5 to <12 years. An interval of at least 8 weeks is recommended between doses for this age group partly because it is expected give an optimal immune response.

Each multidose vial (with an orange cap) contains 1.3 ml and should be diluted with 1.3 ml 0.9% NaCl. Once reconstituted, each reconstituted vials will supply ten doses of 0.2 mL. If the amount of vaccine remaining in the vial cannot provide a full 0.2 mL dose, discard the vial and any excess volume. Do not pool excess vaccine from multiple vials.

An observation period following vaccination of at least 15 minutes is recommended (see section ‎5.6.2). This is to ensure that any anaphylactic-type reactions can receive prompt treatment.

This vaccine is latex-free. The vial stopper is made with synthetic rubber (bromobutyl), not natural rubber latex.

Preparing mRNA-CV multi-dose vial

Note that the process for drawing up mRNA-CV differs from the recommendations for other multi-dose vial vaccines as described in section ‎A7.2 in Appendix 7. To follow international guidance around the use of low dead space needles, the needle used to draw up mRNA-CV is also used to administer the injection. Unless you plan to administer the vaccine dose immediately, carefully replace the needle guard and place syringe onto a ridged tray for storage, for example, if all six doses are prepared at one go in a mass vaccination setting.

For detailed instructions for mRNA-CV multi-dose vial preparation and administration see the most current IMAC COVID-19 education factsheets ‘Instructions for multi-dose vial Pfizer/BioNTech vaccine: preparation and administration’ and ‘Paediatric Pfizer/BioNTech mRNA-CV 10µg Vaccine Preparation’ available from the COVID-19 Education website.

Adjuvanted recombinant COVID-19 vaccine – Nuvaxovid (Novavax)

A primary course of two 0.5 ml doses of adjuvanted rCV are given intramuscularly at least 21 days apart. All individuals from the age of 12 years, who cannot have mRNA-CV, are recommended to receive two doses of rCV from eight weeks apart.

This vaccine has been approved by Medsafe for use as a primary course for individuals aged 12 years and older. See section 5.5.2 for prescribing information.

The ready-to-use multidose vials (with blue cap) contain ten doses. The vials do not require dilution or reconstitution. Do not pool excess from multiple vials. For detailed instructions for adjuvanted rCV multidose vial administration see the most current IMAC COVID-19 education factsheet, ‘Guidance for Novavax COVID-19 vaccine preparation’ available from the COVID-19 Education website.

This vaccine is latex-free. The vial stopper is made with bromobutyl or chlorobutyl rubber, not natural rubber latex.

Coadministration with other vaccines

There are no anticipated safety concerns regarding coadministration any of the currently available COVID-19 vaccines (mRNA-CV (10 µg or 30 µg) or rCV) with other vaccines. These vaccines can be administered at any time before, after or simultaneously (in separate syringes, at separate sites) with other Schedule vaccines including MMR, varicella, influenza, HPV, Tdap and meningococcal vaccines. Note: Due to limited experience at this time, it is recommended to allow spacing of at least three days between rCV and rZV (Shingrix) and adjuvanted influenza vaccine (Fluad Quad).

TST/Mantoux testing for tuberculosis can also be conducted at any time before, after or simultaneously with mRNA-CV or rCV.

5.5. Recommended immunisation schedule

The COVID-19 vaccines were initially only available according to a prioritisation schedule for defined groups, however, since January 2022, all individuals in New Zealand aged from 5 years are eligible to be vaccinated.

For up-to-date details around vaccine policy statements and further clinical guidance for the COVID-19 Vaccine Immunisation Programme refer to COVID-19: Vaccine policy statements and clinical guidance.

Table 5.1: Recommended schedule for COVID-19 vaccination
Shade boxes – recommended but off-label and requires prescription and written consent preferred; dash = not required

Group

Agea

Primary doses
1 and 2b

Primary dose 3c

Booster dose 1

Booster dose 2

General population

5-11 years

8 weeks apartb

-

-

-

12-15 years

8 weeks apartb

-

-

-

16-17 years

8 weeks apartb

-

give from 6 months after previous dose

-

18-64 years

8 weeks apartb

-

give from 3 months after previous dose

can be given age 50 and over years, from 6 months after previous dose

Pregnant women

any age

8 weeks apartb

-

as age appropriate

-

Older adults

from 65 years

8 weeks apartb

-

give from 3 months after previous dose

recommended, give from 6 months after previous dose

Māori or Pacific People

from 40 years

Resident of age or disability care facility

from 16 years

Frontline health care, age care or disability workers

from 16 years

8 weeks apartb

-

give from 3 months after previous dose

can be given age 30 years and over, from 6 months after previous dose

Severely
immune compromisedc,d

5–11 years

8 weeks apartb

give 8 weeks after dose twod

-

 

12–15 years

8 weeks apartb

See footnote e

 

from 16 years

give 3 months after previous dose

recommended, give from 6 months after previous dose

Additional groups at increased risk of severe COVID-19f

from 16 years

8 weeks apartb

give 8 weeks after dose twod

give 3 months after previous dose

recommended, give from 6 months after previous dose

Following SARS-CoV-2 infection

from age 5 years

Complete vaccination course as above. Defer next dose for 3 calendar months after recovery from acute illness or positive SARS-CoV-2 test if asymptomatic (see sections 5.5.8 and 5.5.11)

  1. mRNA-CV can be given from age 5 years. rCV can be given from age 12 years, if preferred or indicated (note that when these vaccines are given as part of a mixed primary or booster schedule, a prescription may be required for off-label use, and written consent recommended (see sections below).
  2. Ideally, give 8 weeks apart. Give mRNA-CV or rCV a minimum of 21 days apart if a shortened schedule is required (eg, due to planned immunosuppression, required for international travel or at very high risk from exposure to COVID-19).
  3. Certain individuals with severe immunosuppressive conditions or treatments are eligible for up to five doses (three primary and two booster doses). See section 5.5.9.
  4. The timing of this dose also needs to consider current or planned immunosuppressive therapies. If the period of least immunosuppression is less than eight weeks, the vaccination can be given any time from four weeks after dose two. See section 5.5.9.
  5. A booster dose may be considered for individuals aged 12–15 years if clinically indicated, this dose will require a prescription. Give 3–6 months after previous dose. See section 5.5.11.
  6. Including those with medical condition or living with disability with significant or complex health needs. See section 5.5.11 and Table 5.4 for further groups recommended a second booster dose due to increased risk of severe breakthrough COVID-19.

5.5.1. mRNA COVID 19 vaccine – Comirnaty (Pfizer/BioNTech)

mRNA-CV (30 µg) for ages from 12 years (purple cap)

All individuals from the age of 12 years are recommended to receive two doses of mRNA-CV given six to eight weeks apart. In situations where the longer interval is not possible (eg, prior to planned immunosuppression, required for urgent international travel or at very high risk from exposure to SARS-CoV-2), give the second dose a minimum of 21 days after first.

Full immunity from the primary course develops from around seven days after the second dose. For booster doses, see section 5.5.11.

mRNA-CV (10 µg) for ages 5 to 11 years (orange cap)

Two doses mRNA-CV (10 µg) given at least 8 weeks apart to children aged from 5 years up to 11 years. In situations where the longer interval is not possible (eg, prior to planned immunosuppression, required for urgent international travel or at very high risk from exposure to SARS-CoV-2), give the second dose a minimum of 21 days after first.

For children who turn 12 years after their first dose, it is recommended to give an age-appropriate vaccine (ie, mRNA-CV (30µg) for the second or subsequent doses, maintaining an eight-week gap between doses.

A mRNA-CV (3µg) formulation (maroon cap) has been approved for use in children aged younger than 5 years in New Zealand. The use of this vaccine will be limited to young children who are at highest risk of severe disease if they were to catch COVID-19.

5.5.2. Adjuvanted recombinant COVID-19 vaccine – Nuvaxovid (Novavax)

The preferred vaccine for the Schedule is mRNA-CV, however, adjuvanted rCV can be offered (if not contraindicated, see section 5.6), where available, to individuals aged from 12 years who are contraindicated mRNA-CV or have experienced an adverse reaction to the first dose of mRNA-CV. It can also be offered to individuals who have declined mRNA-CV and would prefer an alternative vaccine. Individuals opting for this vaccine are recommended to discuss the benefit and potential risks of receiving this vaccine with a health professional. 

The following gives details of approved and off-label use of rCV.

  • A (homologous) primary course two doses of rCV from age 12 years – no prescription is required.
  • For a mixed (heterologous) primary course when a different COVID-19 vaccine dose was given previously – a further primary dose with rCV (if considered appropriate by a clinician, see section ‎5.5.11) is an off-label use and will require prescription from an authorised provider (under regulation s25 of the Medicines Act 1981).
  • Booster dose(s) following any previous COVID-19 vaccine for individuals aged 18 years or older – no prescription required.
  • Booster doses are not yet approved for ages 12–17 years.

Written consent is recommended when a prescription for any doses is required.

5.5.3. Breastfeeding

As with all schedule vaccines, there are no safety concerns about giving mRNA-CV to those lactating. There is limited data to date around the use of adjuvanted rCV in lactation. 

5.5.4. Pregnancy

Anyone who is pregnant or planning pregnancy is encouraged to be routinely vaccinated with mRNA-CV at any stage of pregnancy. The risk of an adverse outcomes from COVID-19 infection during pregnancy is significantly higher compared to age-matched non-pregnant adults (see section ‎5.2.2).[27] International evidence from large quantities of safety surveillance has found no safety concerns with administering mRNA-CV in any stage of pregnancy including no safety concerns of the infant.[85, 86, 87, 88] There is also evidence of antibody transfer in cord blood and breast milk which can offer protection to infants through passive immunity.[61, 89, 90, 91] Infants born to those vaccinated in pregnancy have some protection from COVID-19-associated hospitalisation for up six months.[92]

Those who are pregnant and have questions or concerns are encouraged to discuss them with their health professional. People who are trying to become pregnant do not need to avoid pregnancy after receiving mRNA-CV.

There are no known safety concerns, but due to limited experience, rCV is not currently recommended for use in pregnancy – see Precautions (section 5.6.2).

For information about booster doses in pregnancy, see section 5.5.11.

5.5.5. Frail elderly individuals

In general, it is recommended that all eligible adults including the frail and elderly with comorbidities are offered vaccination against COVID-19, if there are no contraindications to its administration (see section 5.6.1), to provide protection for the individual as well as their community.

5.5.6. Individuals receiving cardiology care

It is recommended that all individuals from age 12 years receive two doses of mRNA-CV (30 µg) given at least 21 days apart, preferably six to eight weeks apart. Children aged 5–11 years are recommended two doses of paediatric mRNA-CV (10 µg) given at least 8 weeks apart. Pre-existing cardiac conditions, in general, are not regarded as precautions or contraindications to vaccination. This includes pre-existing rheumatic heart disease. Note that many cardiac conditions increase the risk from COVID-19 disease. Those with a history of pericarditis or myocarditis, unrelated to mRNA-CV, can have the vaccination if the condition is completely resolved, (ie, no symptoms and no evidence of ongoing cardiac inflammation). See section 5.6.2 for those who have myocarditis associated with mRNA-CV.

For those with a history of myocarditis and pericarditis related to mRNA-CV, seek specialist immunisation advice on a case-by-case basis to consider an appropriate alternative vaccine (eg, rCV from age 12 years) or no further vaccination, and about timing of further doses.

5.5.7. Vaccination following SARS-CoV-2 infection

Vaccination should be offered regardless of an individual’s history of symptomatic or asymptomatic SARS-CoV-2 infection. As the duration of protection post infection is currently unknown, vaccination is recommended. Although, there are no specific safety concerns around giving mRNA-CV to individuals with a history of SARS-CoV-2 infection or symptomatic COVID-19, those who have had recent infection can experience more systemic reactogenicity after the first dose of mRNA-CV (see section ‎5.7.1).[93] Viral or serological testing is not required before vaccination.

A person aged from 5 years who has had prior SARS-CoV-2 infection is recommended to complete the full vaccination course of mRNA-CV (or another COVID-19 vaccine, as available). In these individuals, vaccination is recommended to be continued from three calendar months after recovery from acute illness, or three months from the first confirmed positive test if asymptomatic. This applies to any dose of the primary course or booster doses, as age appropriate. Based upon clinical discretion, where the individual is at high risk of severe disease from reinfection and has not completed the full course, vaccination can be delivered sooner than three months after SARS-CoV-2 infection and completed with the recommended spacing between doses.

For all other vaccines, vaccination can commence as soon as the individual is no longer acutely unwell and when cleared to leave isolation.

5.5.8. Individual with immunodeficiencies or receiving immunosuppressive agents

There are no safety concerns around administering mRNA-CV or rCV to individuals who are immunocompromised and/or receiving immunosuppressive agents. As with other non-live vaccines, the antibody response to these vaccines may be reduced and protection may be suboptimal but, it is likely to be adequate to protect against severe disease. It is recommended to discuss the optimal timing for vaccination with a specialist before the vaccine appointment for those who are severely immunocompromised. Ideally, vaccination should be conducted prior to any planned immunosuppression (see section ‎4.3.7).

It is important that all close contacts of immunocompromised individuals aged from 5 years are up to date with immunisations. Close contacts aged from 18 years should also receive a booster dose at least three calendar months after their primary course and those aged 16–17 years should receive a booster dose at least six months after their primary course. For booster doses, see section ‎5.5.11.

Individuals who are severely immunocompromised

A third primary dose of mRNA-CV (10 µg or 30 µg, as age-appropriate) is indicated for certain individuals aged from 5 years who are severely immunocompromised who are likely to have not responded adequately to the first two doses. Serology is not recommended. This third primary dose is distinct from the booster dose (for booster doses see section 5.5.11).

Preferably, this third dose should be administered at least eight weeks after the second dose. However, the timing also needs to consider current or planned immunosuppressive therapies. If the period of least immunosuppression is less than eight weeks, the vaccination can be given any time from four weeks after dose two. Where possible, delay the third dose until two weeks after the period of immunosuppression (in addition to the clearance time-period of therapeutic). If this is not possible, consider vaccination during a treatment ‘holiday’ or at a nadir of immunosuppression between doses of treatment.

These additional doses are currently considered off label and can only be offered by an authorised prescriber with informed, preferably written, consent (under regulation s25 of the Medicines Act 1981). This is under review with Medsafe. For further guidance see COVID-19: Vaccine policy statements and clinical guidance.

If a significant adverse reaction to mRNA-CV has occurred that contraindicates further mRNA-CV doses, then rCV may be considered for a third primary dose for those aged from 12 years (if not contraindicated) who are severely immunocompromised. This also requires prescription and written consent is recommended. It is recommended to seek advice from IMAC.

Table 5.1 provides guidance on types of immunocompromise for which a third primary dose is recommended. For further information on corticosteroid indicative dosages and examples of non-corticosteroid agents considered immunosuppressive, see section below and Table 5.2.

Table 5.2: Individuals (aged 5 and older) with severe immunocompromise recommended to receive a third primary dose of mRNA-CV (10 µg or 30 µg, as age-appropriate)
Note: This list is not exhaustive but provides guidance on scenarios where a third primary dose is recommended. There is variation between individuals in response to immunosuppressive or immunomodulating therapy. Clinicians may use their judgement for conditions or medications that are not listed here that are associated with severe immunocompromise.

Eligible group / indication

Treatments or health status

Individuals with primary or acquired immunodeficiency states at the time of vaccination

Acute and chronic leukaemia and clinically aggressive lymphomas (including Hodgkin’s lymphoma)

under treatment, or within 12 months of achieving cure or remission

Chronic lymphoproliferative disorders, including haematological malignanciesa and plasma cells dyscrasias

under specialist follow up

Active HIV infection / AIDS

current CD4 count <200 cells/µl

Primary or acquired cellular and combined immune deficiencies

lymphopenia (<1,000 lymphocytes/µl) or

functional lymphocyte disorder.

Allogenic or autologous haematopoietic stem cell transplant

received in previous 24 months or

received >24 months ago but had ongoing immunosuppression or graft-versus-host disease.

Persistent agammaglobulinaemia due to primary immunodeficiency and secondary to disease/therapy

IgG <3 g/L

Individuals on, or recently on, immunosuppressive therapy at the time of vaccination

Following a solid organ transplant

receiving therapy

B cell depleting biologic therapy, including rituximab

receiving or received therapy in the previous 6 months

Biologics or targeted therapyb for autoimmune or autoinflammatory disease

received within the previous 3 months

Immunosuppressive cytotoxic chemotherapy or immunosuppressive radiotherapy for any indication

received within the previous 6 months

Individuals with chronic immune-mediated inflammatory disease who were receiving or had received immunosuppressive therapy prior to vaccination

High-dose or long-term moderate dose corticosteroids
(for indicative dosages, see below)

for more than a week in the month before vaccination

For select immunosuppressant drugsb,c

in previous 3 months

Certain combination therapies at where cumulative effect is severely immunosuppressive, as determined by clinical judgment

in previous 3 months

 

Individuals receiving long term haemodialysis or peritoneal dialysis

  1. Such as indolent lymphoma, chronic lymphoid leukaemia, myeloma, Waldenstrom’s macroglobulinemia and other plasma cell dyscrasias. Note this list is not exhaustive but provides an indication of conditions where an individual is recommended to receive a third primary dose.
  2. For examples, see Table 5.2
  3. excluding hydroxychloroquine, sulfasalazine, or mesalazine, when used as monotherapy.

Individuals receiving corticosteroids

A third primary dose of mRNA-CV is recommended for individuals with chronic immune-mediated inflammatory disease who are receiving or have received high dose or long-term moderate doses of corticosteroids prior to vaccination, for example:

  • high dose – equivalent to at least 20 mg prednisolone per day for more than ten days, in previous month
  • moderate dose – equivalent to at least 10 mg prednisolone per day for more than four weeks, in previous three months
  • also includes for those who received high dose corticosteroids for any reason – equivalent to at least 40 mg per day for more than a week, in the previous month.

Individuals for whom third primary dose is not routinely recommended include those who require:

  • brief corticosteroid therapy, for example for asthma, chronic obstructive pulmonary disease or COVID-19 – equivalent to 40mg or less prednisolone per day
  • low locally acting corticosteroids, inhaled or topical
  • replacement corticosteroid treatment for adrenal insufficiency.

Clinical judgement is required to determine the level of immunosuppression and these dosages are only indicative examples. In some cases, combinations of therapies can have a cumulative effect that is severely immunosuppressive.

Individuals receiving non-corticosteroid immunomodulatory agents

A third primary dose of mRNA-CV is recommended for individuals with chronic immune-mediated inflammatory diseases who were receiving or had received immunosuppressive therapy prior to primary COVID-19 vaccination. Indicative examples are given in Table 5.2. Clinical judgement is required to determine the level of immunosuppression. In some cases, combinations of therapies can have a cumulative effect that is severely immunosuppressive.

Table 5.3: Examples of non-corticosteroid immunosuppressant therapies for which a third primary dose of mRNA-CV is recommended or not routinely recommended
Clinicians may use their judgement for conditions or medications that are not listed here that are associated with severe immunocompromise and in some cases based on dosages or combinations of therapies

Examples of non-corticosteroid agents for which a third dose is recommended

Agent

Example

Mycophenolate, methotrexate, leflunomide,
6-mercaptopurine

 

Thiopurines

azathioprine

Alkylating agents

cyclophosphamide

Systemic calcineurin inhibitors

cyclosporin, tacrolimus

BTK inhibitors

ibrutinib

JAK inhibitors

ruxolitinib

Anti CD20 antibodies

rituximab, obinutuzumab, ocrelizumab

Sphingosine 1-phosphate receptor modulators

fingolimod

Anti-CD52 antibodies

alemtuzumab

Anti-complement antibodies

eculizumab

Anti-thymocyte globulin

 

Examples of non-corticosteroid agentsa for which third primary dose is not routine recommended

Agent

Example

Anti-integrins

natalizumab

Anti-TNF-α antibodies

infliximab, adalimumab, etanercept

Anti-IL-1 antibodies

anakinra

Anti-IL-6 antibodies

tocilizumab

Anti-IL-17 antibodies

secukinumab

Anti-IL-4 antibodies

dupilumab

Anti-IL-23 antibodies

ustekinumab

  1. For immune checkpoint inhibitors see section 4.3.2

5.5.9. Revaccination

Individuals from age 5 years who have undergone haematopoietic stem cell transplantation since their first course can be revaccinated with a full (three dose) primary course of a COVID-19 vaccine, plus booster as age appropriate (preferably with age-appropriate mRNA-CV).

Based on clinical discretion, if all scheduled doses have been completed prior to commencement of chemotherapy or solid organ transplant, a single further dose of mRNA-CV can be given from the age of 5 years.

5.5.10. Booster doses

All individuals aged 16 years and over are recommended to receive a booster dose.  For those aged 18 years and above, a single dose of mRNA-CV (30 µg) is recommended to be given at least three calendar months after completion of the two-dose primary course. In cases where confirmed SARS-CoV-2 infection occurs between dose two of the primary course and booster dose, give a single dose of mRNA-CV from three calendar months after recovery from COVID-19, or at least three calendar months from the first confirmed positive PCR test if asymptomatic (see section ‎5.5.8).

For those aged 16–17 years, a single dose of mRNA-CV (30 µg) is recommended to be given at least six months after completion of the primary course. If SARS-CoV-2 infection occurs later than three months after primary course, give a booster dose at least three calendar months after recovery from acute illness or positive test in asymptomatic (see section ‎5.5.8) to provide the longest gap.

A booster dose is particularly recommended for individuals most at risk of exposure to SARS-CoV-2 or most at risk of serious COVID-19, as outlined below.

  • Frontline health care workers, particularly those most likely to be exposed to COVID-19 in the community or in regions where further risk of spread of SARS-CoV-2 is high.
  • All individuals who are aged 65 years or over.
  • Māori and Pacific People due to a greater risk of severe disease, especially if aged from 40 years or over.
  • Anyone aged 16 years or over at increased risk of severe COVID-19:
    • eligible for funded influenza vaccine, including pregnancy (See Booster doses in pregnancy)
    • disabled or caring for a person with a disability
    • severely obese (BMI ≥40 kg/m2)
    • hypertension, requiring two or more medications to control
    • in a custodial setting
    • have been diagnosed with a severe mental illness (including schizophrenia, major depressive disorder, bipolar disorder or schizoaffective disorder, and adults currently accessing secondary and tertiary mental health and addiction services).

Individuals aged from 16 years who are severely immunocompromised who received a third primary dose are recommended to also be given the booster dose at least three calendar months later, taking in consideration current or planned immunosuppressive therapies. A booster dose given prior to six months after the primary course to those aged 16–17 years is considered off-label and requires a prescription.

A booster dose is not currently approved as part of the COVID-19 vaccination programme for individuals aged under 16 years. A booster dose can be considered for those aged 12–15 years who are at higher risk of severe COVID-19, to be given from three to six months after completing the primary course. This is an off-programme use requiring a prescription and written consent is recommended. For underlying health conditions that increase risk for severe COVID-19 in children see Starship guidelines for COVID-19 disease in children. This list is not exhaustive and clinicians may use their judgement for conditions that are not listed.

Although mRNA-CV is the preferred vaccine, rCV can also be used as a booster dose, if not contraindicated for those aged from 18 years. A prescription is not required for this use.

Certain individuals with severe immunosuppression are recommended to receive three primary doses with the third dose given at least eight weeks after dose two (see section ‎5.5.9; this is not the same as booster doses).

Second booster dose

Due to the risk from waning protection, notably during the winter season, certain individuals aged from 16 years who are at highest risk from severe breakthrough COVID-19 are recommended to have a second booster dose of mRNA-CV to be given at least six months since their previous booster dose. These include:

  • people of Māori or Pacific ethnicities aged 40 years and over
  • all other individuals aged 50 years and over
  • residents aged 16 years or over living in aged care and disability care facilities
  • severely immunocompromised people who were eligible to receive a third primary dose and fourth dose as a first booster (see section 5.5.9; ie, this group is eligible for five doses)
  • individuals aged from 16 years who have certain medical conditions (see Table 5.4) that increase the risk of severe breakthrough COVID-19 illness.
  • individuals aged from 16 years who live with disability with significant or complex health needs or multiple comorbidities (see Table 5.4).

A second booster dose is also available for:

  • people of Māori or Pacific ethnicities aged 40 years and over
  • all people aged 50 years and over
  • health care, aged care and disability workers aged 30 years and over.

As with previous doses, a second booster dose, if due, should be postponed for three months after SARS-CoV-2 infection. Ideally, to be given from six months after previous vaccination or three months after infection whichever is the longest time since exposure to SARS-CoV-2 antigens. Clinical discretion can be applied when considering vaccination prior to 3 months after infection. This may be appropriate for those individuals considered to be at high risk of severe disease from COVID-19 re-infection.

If indicated or preferred, rCV can be given as a second booster dose from age 18 years instead of mRNA-CV.

Table 5.4: Additional groups recommended for a second booster dose of COVID-19 vaccine (adapted from ATAGI)
People in these groups are likely to have ongoing increased risk of severe COVID-19 even after primary vaccination. These examples are not exhaustive, and providers may include individuals with conditions similar to those listed below, based on clinical judgement.

Category

Examples

Immunocompromising conditions

including people living with HIV infection

Cancer

Non-haematological cancer including those diagnosed within the past 5 years or on chemotherapy, radiotherapy, immunotherapy or targeted anti-cancer therapy (active treatment or recently completed) or with advanced disease regardless of treatment. Survivors of childhood cancer.

Chronic inflammatory conditions requiring medical treatment with disease-modifying anti-rheumatic drugs (DMARDs) or immune-suppressive or immunomodulatory therapies.

Systemic lupus erythematosus, rheumatoid arthritis, Crohn’s disease, ulcerative colitis, and similar who are being treated.

Chronic lung disease

Chronic obstructive pulmonary disease, cystic fibrosis, interstitial lung disease and severe asthma (defined as requiring frequent hospital visits or the use of multiple medications).

Chronic liver disease

Cirrhosis, autoimmune hepatitis, non-alcoholic fatty liver disease, alcoholic liver disease.

Severe chronic kidney disease (stage 4 or 5)

 

Chronic neurological disease

Stroke, neurodegenerative disease (eg, dementia, motor neurone disease, Parkinson’s disease), myasthenia gravis, multiple sclerosis, cerebral palsy, myopathies, paralytic syndromes, epilepsy.

Diabetes mellitus requiring medication

 

Chronic cardiac disease

Ischaemic heart disease, valvular heart disease, congestive cardiac failure, cardiomyopathies, poorly controlled hypertension, pulmonary hypertension, complex congenital heart disease.

People with disability with significant or complex health needs or multiple comorbidities which increase risk of poor outcome from COVID-19

Particularly those with trisomy 21 (Down Syndrome) or complex multi-system disorders.

Severe obesity with BMI ≥40 kg/m2

 

Severe underweight with BMI <16.5 kg/m2

 

Booster doses in pregnancy

Pregnant women aged from 16 years can receive a booster dose of mRNA-CV at any stage of pregnancy (from three calendar months after a primary course if aged 18 years or over, or from six months if aged 16–17 years). Although the use of booster doses in pregnancy is limited to date, as with the primary course, it is expected to be safe and effective. If the full primary course has been given in pregnancy, a booster can be given as time-appropriate before or after delivery, and at least three calendar months after completion of their primary course. Those who are pregnant are encouraged to discuss timing of a booster dose with their health professional. A booster dose given earlier than six months after the primary course to those aged 16–17 years, is considered off-label and requires a prescription and written consent is recommended. Second booster doses are not currently recommended to be given during pregnancy to healthy individuals without medical conditions or who do not meet other criteria given above (see Second booster dose and Table 5.4).

5.6. Contraindications and precautions

See also section ‎2.1.3 for pre-vaccination screening guidelines and section ‎2.1.4 for general contraindications for all vaccines.

5.6.1. Contraindications

Vaccination with mRNA-CV or rCV is contraindicated for individuals with a history of anaphylaxis to any component or previous dose the same vaccine.

5.6.2. Precautions

A definite history of immediate allergic reaction to any other product is considered as a precaution but not a contraindication to vaccination with COVID-19 vaccines (mRNA-CV or rCV). A slightly increased risk of a severe allergic response in individuals who have had a previous anaphylaxis-type reaction needs to be balanced against the risk of SARS-CoV-2 exposure and severe COVID‑19. These individuals can still receive a COVID-19 vaccines, if not contraindicated, and observation extended to 30 minutes after vaccination in health care settings, where anaphylaxis can be immediately treated with adrenaline.

When vaccinating an elderly person who has an intercurrent or comorbid condition, ensure they are stabilised or as well as possible before they have the vaccine. Following vaccination ensure good hydration and careful management of potential systemic adverse events, such as fever. It is advisable for them to be with someone else for 24 hours after receipt of the vaccine to help manage potential adverse events.

Myocarditis or pericarditis

If myocarditis, myopericarditis or pericarditis occurs after a dose of mRNA-CV or rCV, defer further doses of COVID-19 vaccination. Seek specialist immunisation advice, on a case-by-case basis, to consider an appropriate alternative vaccine or no further vaccination, and about timing for further primary or booster doses. Vaccination is not recommended for anyone with current active cardiac inflammation.

Pregnancy

There is insufficient safety data to recommend rCV for use during pregnancy. Those who are pregnant are advised to discuss the benefit and potential risks of receiving this vaccine in pregnancy with their health professional. There are no safety concerns should it be given inadvertently in pregnancy.

5.7. Potential responses and AEFIs

5.7.1. Potential responses

mRNA COVID 19 vaccine – Comirnaty (Pfizer/BioNTech)

Commonly reported responses to mRNA-CV (30 µg) during clinical trials and post-licensure surveillance are injection-site pain, headache, dizziness and fatigue; other responses included muscle aches, feeling generally unwell, chills, fever, chest discomfort, joint pain, nausea and axillar lymph node swelling. These occurred most often after dose two and in younger adults (aged 18–55 years), and within one or two days of vaccination. Most are mild or moderate in severity and are self-limiting.[49, 94] Analgesia, such as paracetamol or ibuprofen (as appropriate), can be taken for pain and discomfort following vaccination. It is advisable to limit vigorous exercise if feeling unwell.

During clinical trials, the responses in children aged 5–11 years given paediatric formulation mRNA-CV (10 µg) were similar to those seen for the adult formulation mRNA-CV (30 µg) in those age 16–25 years. Generally, reactions were mild to moderate and short-lived. Pain at injection site was commonly reported (by over 70 percent) after dose one and two. Overall fewer children reported systemic reactions than seen after the 30 µg dose in adults, with fever, fatigue, headache, chills and muscle ache as the most common and more frequent after the second dose.[48] These responses were mirrored in reports to VAERS and V-safe after 8.7 million doses given routinely to children in the US.[95]

See chapter 2 (section 2.3.3) for immunisation-stress related responses (ISRR).

Adjuvanted recombinant COVID-19 vaccine – Nuvaxovid (Novavax)

The most reported responses to rCV in clinical trials were injection-site tenderness and pain, headache, fatigue, myalgia, malaise, arthralgia, nausea and vomiting. These reactions were more common after dose two, lasting for one to three days, and occurred at higher incidence in younger age groups (less than 65 years).[65]

Breast screening and CT scans

Transient unilateral axillary adenopathy, a known response to vaccination, was particularly noted following vaccination with mRNA-CV due to the scale of the roll-out and age groups being immunised. Early estimates suggest that 12–16 percent of vaccine recipients experience axillary adenopathy after vaccination with mRNA-CV, starting one or two days after vaccination and which can persist for several weeks.[96, 97] Lymphadenopathy has also been commonly reported after booster doses of mRNA-CV.[98]

When attending breast screening and mammography appointments, it is recommended that individuals advise the radiographer or doctor that they have received a COVID-19 vaccine recently. It is advised to monitor any lymph node changes that persist for longer than six weeks after vaccination.[96]

Likewise, individuals undergoing FDG PET/CT scans for cancer screening are advised to inform the radiologist or their oncologist that they have been recently vaccinated, or, if possible, to have COVID-19 vaccination at least two weeks before a scheduled scan or as soon as possible afterwards. Treatment should not be delayed.

5.7.2. AEFIs

Adverse events following immunisation (AEFIs) with the COVID-19 vaccines are being closely monitored during clinical trials and by post marketing surveillance. A dedicated COVID-19 vaccine AEFI reporting tool is available online from CARM (see section 1.6.3). Medsafe reports weekly on the AEFI reported to CARM after COVID-19 vaccinations (see the Medsafe website).

A list of adverse events of special interest (AESIs), including those previously associated with immunisation in general and with the individual vaccine platforms, was created by Safety Platform for Emergency Vaccines (SPEAC) in collaboration with the Coalition for Epidemic Preparedness Innovations (CEPI) and based on existing and new Brighton Collaboration case definitions. For further information, see the Brighton Collaboration website. Global pharmacovigilance and active safety monitoring systems continue to watch for both AESI and unexpected AEFI.

mRNA COVID 19 vaccine – Comirnaty (Pfizer/BioNTech)

Overall, no AESI signals were detected by the Vaccine Safety Datalink in the US up to 21 days after vaccination, following the administration of over 13 million doses of mRNA-CV (Comirnaty), however, subgroup analyses did find mRNA-CV to be associated with a slight increase in myocarditis and pericarditis in younger people (aged under 30 years).[99, 100]

Preliminary phase II/III clinical trial safety data reported lymphadenopathy in 64 (0.3%) vaccine recipients and six (<0.1%) placebo recipients (follow-up of up to 14 weeks after second dose of a subset of 18,860 participants who received at least one dose of mRNA-CV). Four vaccine-related adverse events were recorded (namely, shoulder injury related to vaccine administration, lymphadenopathy local to injection site, paroxysmal ventricular arrhythmia and right leg paraesthesia). No deaths were related to either the vaccine or the placebo.[49] During clinical trial follow-up to 1 February 2021, acute peripheral facial paralysis (Bell’s palsy) was reported by four vaccinated participants and none in the placebo group.[101] No safety signal has been detected for this condition as an AESI,[102] and safety monitoring is ongoing.

No vaccine-related severe adverse events were seen during the phase II/III clinical trial of mRNA-CV (10 µg) in 1,518 children aged 5–11 years. Lymphadenopathy was reported in ten (0.9 percent) of mRNA-CV (10 µg) recipients. Rashes, with no consistent pattern, considered related to the vaccination were observed in four participants; these were mild and self-limiting with typical onset seven or more days after vaccination. No differences were apparent in vaccine safety between the children who had baseline evidence of previous SARS-CoV-2 infection.[48] As of 19 December 2021 following administration of approximately 8.7 million doses of mRNA-CV (10 µg) in children aged 5–11 years in the US, the majority of reports to VAERS (97.6 percent) were non-serious and 2.4 percent were serious. The most common non-serious reports were due to vaccine administration errors. Of the serious reports, 11 verified cases of myocarditis were reported to VAERS but no chart-confirmed myocarditis cases were reported through the Vaccine Safety Datalink in this age group.[95] Post-licensure surveillance is ongoing internationally.

Myocarditis and pericarditis

A small increase in incidence of myocarditis, myopericarditis and pericarditis has been observed following the second dose of mRNA-CV vaccination (40.6 cases per million doses in young males and 4.2 cases per million in young females, aged 12–29 years, decreasing to 2.4 and 1.0 per million, respectively, in men and women aged over 30 years).[103] Most cases occur within 14 days of vaccination typically with full recovery after standard treatment and rest.[104, 105] A review of clinical records in the US observed the median time to onset for myocarditis was 3.5 days (interquartile range 3.0–10.8 days) after vaccination and a median of 20 days (range 6.0–41 days) for pericarditis.[105] Wider spacing between doses (ie, eight weeks) has been shown to significantly lower the risk of myocarditis in young adults in Canada.[106]

Myocarditis and pericarditis are uncommon conditions considered to be associated with viral infection, including COVID-19. Recently vaccinated individuals should seek immediate medical attention if they experience new onset of (acute and persisting) chest pain, shortness of breath or arrhythmia (palpitations). Diagnosis is based on elevated troponin, C-reactive protein and electrocardiogram and/or MRI findings. Report all suspected cases to CARM as Medsafe continues to monitor this AEFI closely. Defer further doses of mRNA-CV if myocarditis or pericarditis occurs after vaccination. Seek specialist immunisation advice, on a case-by-case basis, to consider an appropriate alternative vaccination option, and timing for further primary or booster doses (see section 5.6.2).

Anaphylaxis

Following approval for use in the US, the VAERS detected 47 cases of anaphylaxis after administration of just under ten million doses (around five cases per million doses) mRNA-CV (Pfizer/BioNTech). The median interval to symptom onset was ten minutes (range <1–1140 minutes), almost 90 percent occurred within 30 minutes of vaccination.[107] All were successfully treated with adrenaline. See section 5.6 for contraindications and precautions.

Frail elderly

A follow-up, after approximately two million doses of mRNA-CV were delivered through long-term residential care facilities to elderly and frail residents in the US found no increase in deaths post vaccination.[43] Deaths were to be expected and consistent with the all-cause mortality rate and causes of death for these individuals, who have multiple comorbidities, declining health and require end-of-life care.[43] There are no added safety concerns about the use of this vaccine in the elderly.[108]

History of Guillain-Barré Syndrome

There is no evidence of a higher rate of reporting of Guillain-Barré syndrome (GBS) following COVID-19 vaccination in individuals who have previously had GBS. Vaccination with mRNA-CV is preferred.

Adjuvanted recombinant COVID-19 vaccine – Nuvaxovid (Novavax)

Uncommon AEFI reported during clinical trials were lymphadenopathy, hypertension (observed in 1 percent of older adults for three days following vaccination), rash and injection site pruritus. One case of myocarditis was observed in a clinical trial occurring three days after second dose was deemed by the independent safety monitoring committee to most likely be viral myocarditis. No episodes of anaphylaxis were reported.[65] Three cases of myocarditis or myopericarditis and two cases of pericarditis were reported during two clinical trials (one case in placebo group) and in two cross-over studies. Although a causal relationship to the vaccine could not be confirmed, the European Medicines Agency listed heart inflammation as a potential risk.[98]

In a clinical trial, when rCV was given as a second dose after a first dose of mRNA-CV, similar systemic responses were observed to those given mRNA-CV as a second dose and local reactions were generally less frequent.[83]

A slightly increased incidence of local adverse events such as injection site tenderness and pain were reported during a clinical trial of rCV given concurrently with seasonal influenza vaccine (65 percent rCV plus influenza vs 53 percent for rCV alone of participants reported tenderness). This component of a randomised, placebo controlled clinical trial included 201 people who received rCV and QIV concurrently and 16 participants aged 65 years or older who received adjuvanted TIV.[63]

5.8. Public health measures

There is an ongoing COVID‑19 pandemic globally. New Zealand has implemented control measures to limit the spread of SARS-CoV-2 in the community as described on the Unite Against COVID-19 website. All individuals with symptoms of COVID‑19 are expected to self-isolate, seek medical advice and be tested for infection. Rapid antigen testing and nasopharyngeal PCR testing continue to be fundamental components of the public health measures. Up to date information on public health measures is available on the Unite Against COVID-19 website.

Immunisation using COVID‑19 vaccines is part of the public health strategy aimed at reducing the risk of severe disease to minimise the burden on the health care system and slowing the rate of transmission during community outbreaks.

5.8.1. Post-exposure prophylaxis and outbreak control

Currently, there is no information on the use of COVID-19 vaccines for post-exposure prophylaxis. Vaccination is available to everyone in New Zealand aged 5 years or older.

5.9. Variations from the vaccine data sheets

Spacing of at least eight weeks between first and second dose is recommended for mRNA-CV and rCV. This differs from the data sheets which recommend an interval of at least 21 days.

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