COVID-19: Vaccine side effects and reactions

Find out the side effects, the reported adverse events and allergic reactions to the Pfizer and Novavax vaccines.

Last updated: 6 June 2023

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Common side effects

Like all medicines, you might experience some mild side effects in the days after getting your vaccination. This is common, and a sign that your body is learning to fight the virus.

Most side effects do not last long, and will not stop you from going about your daily life or having another vaccine dose in the future. Some side effects may temporarily affect your ability to drive or use machinery.

Side effects are reported to the Centre for Adverse Reactions Monitoring (CARM) and Medsafe closely monitors and releases safety reports showing this data.

The top 10 reported side effects of the Pfizer vaccine in New Zealand are:

Reaction Number doses 1-4 Number dose 1 Number dose 2 Number dose 3 Number dose 4
Headache 19,679 6,914 8,252 4,224 289
Dizziness 18,375 9,324 6,153 2,712 186
Injection site pain 16,758 5,583 6,701 4,150 324
Lethargy 14,662 5,508 6,726 2,423 5
Nausea 13,309 5,500 5,063 2,549 197
Chest discomfort 13,289 5,476 4,971 2,711 131
Fever 9,089 2,188 4,387 2,370 144
Influenza-like illness 8,670 2,304 4,093 2,102 171
Shortness of breath 7,625 3,262 2,935 1,344 84
Lymphadenopathy 7,588 1,310 2,912 3,258 108

Timeframe: 20 February 2021 to 30 November 2022

See details in the full Medsafe reports

When you’re likely to experience a side effect

Most side effects appear within a day or two after being vaccinated.

What you may feel What can help When this could start

Pain at the injection site, a headache and feeling tired and fatigued. These are the most commonly reported side effects.

Place a cold, wet cloth, or ice pack on the injection site for a short time.

Do not rub or massage the injection site.

Within 6 to 24 hours

Muscle aches, feeling generally unwell, chills, fever, joint pain and nausea may also occur.

Rest and drink plenty of fluids

Paracetamol or ibuprofen can be taken, follow the manufacturer’s instructions.

Seek advice from your health professional if your symptoms worsen.

Within 6 to 48 hours

New onset chest pain, racing heart, or shortness of breath Speak to your health professional promptly if you develop any of these symptoms. Within 14 days

If you’re concerned about how you’re feeling

If you’re unsure about your symptoms or if they get worse, call Healthline:

Phone 0800 358 5453

If you’re concerned about your safety, call 111. Tell them you’ve had a COVID-19 vaccination so they can assess you properly.

Rare side effects

There are some side effects that are more serious but very rare, like a severe allergic reaction or an inflammation of the heart.

Myocarditis and pericarditis

Myocarditis is inflammation of the heart muscle, while pericarditis is inflammation of the tissue forming a sac around the heart. These conditions are usually caused by viral infections (including COVID-19), but they are also very rare and serious side effects of the Pfizer and Novavax vaccines. 

Symptoms of myocarditis or pericarditis linked to the vaccine generally appear within a few days, and mostly within the first few weeks after having the vaccine. If you get any of these new symptoms after your vaccination, you should seek prompt medical help. If these symptoms don’t go away, seek medical help again. Children are less likely to have these sorts of side effects but may not volunteer symptoms. Caregivers should ask children how they are feeling.

Symptoms may include:

  • tightness, heaviness, discomfort or pain in your chest or neck
  • difficulty breathing or catching your breath
  • feeling faint or dizzy or light-headed
  • fluttering, racing or pounding heart, or feeling like it is ‘skipping beats’.

If you feel any of these symptoms in the days or weeks after the vaccine, you should see a healthcare professional, such as a GP, afterhours service, or emergency department. If your appointment is within 2 weeks of your vaccination there will be no charge for the consultation. If the appointment is more than 2 weeks after, you may be able to receive compensation and your GP can submit an ACC form on your behalf. You can also call Healthline on 0800 358 5453 anytime to get advice.  

If you’re concerned about your safety, call 111. Tell them you’ve had a COVID-19 vaccination so they can assess you properly.

Allergic reactions

There are some side effects that are more serious but rare, like a severe allergic reaction.

Serious allergic reactions or anaphylaxis occur rarely. This is the reason people are observed for around 15 minutes post vaccination. Vaccinators are well-trained in managing these if they occur.

Bell’s palsy

Temporary one-sided facial drooping (Bell's palsy) has been reported as a rare side effect, affecting every 1 in 1,000 to 1 in 10,000 people in the clinical trials.

Serious adverse cases reported 

Medsafe's reports give detailed information about serious adverse cases reported.

See details in the full reports

CARM and Medsafe investigate reports of significant adverse events, including those with a fatal outcome.

The aim of the investigation is for CARM and Medsafe to determine the likelihood the vaccine caused the reported events.

For significant cases, including deaths, the COVID-19 Independent Safety Monitoring Board (CV-ISMB) review the information supplied during the investigation and provide their view on the likely relationship of the reported events to vaccination.

Causes of death are investigated and determined by the coroner – not by CARM or Medsafe.

About the coronial process

The COVID-19 Independent Safety Monitoring Board holds meetings every 3-4 weeks to look at COVID-19 vaccine safety data. They can also call additional meetings if an urgent issue arises internationally or there’s a report of a serious unexpected event.

More information about the Board

How to report side effects

Reporting COVID-19 vaccine side effects means the safety of COVID-19 vaccines within Aotearoa New Zealand can be closely monitored.

You can report your own side effects, or side effects experienced by someone else (including a child). You don’t have to be certain the vaccine caused the side effects to make a report.

Report your side effects

Text invites to submit side effects

If you get a COVID-19 vaccine booster, or a child in your care has had a paediatric (child) COVID-19 vaccine, you may be invited by text to let us know about any side effects experienced in the days after – this is called a ‘Post Vaccine Symptom Check’.

The text invite will come from the Ministry of Health and you’ll be asked to reply ‘YES’, ‘NO’, or ‘STOP. All replies are free of charge.

If you want to take part you’ll be sent a link to an online web form.

In this section

  • A study has been launched to find out if people who developed myocarditis or pericarditis following COVID-19 Pfizer vaccination had long-term health problems. Anyone over 12, with a clinical diagnosis of myocarditis or pericarditis following a Pfizer vaccination, is eligible to participate.    Read more
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