About COVID-19

Information on COVID-19 including symptoms, spread, treatments, immunity and where to get help.

Last updated: 13 September 2022

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What is COVID-19?

COVID-19 is caused by a coronavirus named SARS-CoV-2 that can affect your lungs, airways and other organs. Coronaviruses are a large and diverse family of viruses which cause illnesses such as the common cold.

SARS-CoV-2 was first recognised in China and is thought to have originated in animals. Other recent diseases caused by coronaviruses and thought to be transmitted from animals include severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS)

COVID-19 variants

The SARS-CoV-2 virus that causes COVID-19 has undergone genetic mutations over time. The Omicron variant has spread worldwide rapidly and is now the major variant in many countries, including New Zealand. Omicron is much more transmissible than previous variants of the COVID-19 virus, including Delta.

Read more about COVID-19 variants.

COVID-19 symptoms

Common symptoms of COVID-19 are like those found with illnesses such as a cold or influenza. You may have one or more of the following:

  • new or worsening cough
  • sneezing and runny nose
  • fever
  • temporary loss of smell or altered sense of taste
  • sore throat
  • shortness of breath
  • fatigue/feeling of tiredness

Less common symptoms of COVID-19 may include diarrhoea, headache, muscle aches, nausea, vomiting, malaise, chest pain, abdominal pain, joint pain or confusion/irritability. These almost always occur with one or more of the common symptoms.

Timing of symptoms

After infection with Omicron, about half the people who get symptoms develop them within three days, and almost all of them will within eight days.

Some people who have COVID-19 may not have any symptoms and could still be infectious. 

Some people who develop symptoms can be infectious for approximately one or two days before the symptoms develop.

Read about Long COVID

Where to get help

If you develop COVID-19 symptoms get tested immediately. Read more about COVID-19 testing and find your local testing station at Healthpoint.

If you test positive you will need to isolate for a full 7 days. For most people, symptoms of COVID-19 will be mild and can be managed at home. You can find health advice to help manage your illness on the COVID-19 Health Hub.

If your symptoms get worse or you need urgent medical care, contact your local healthcare provider or call Healthline on 0800 358 5453 24 hours a day, seven days a week.

If you or the person you are caring for develops difficulty breathing, severe chest pain, fainting or becomes unconscious, call 111 immediately.

Read more advice for people with COVID-19 and advice for household and close contacts.

How COVID-19 spreads

The virus that causes COVID-19 is mostly spread in particles that escape from an infected person’s mouth or nose when they breathe, speak, cough, sneeze or sing.

These particles range in size. Larger and heavier particles (droplets) quickly fall to the ground or other surfaces within seconds or minutes. Smaller particles (aerosols) can remain airborne for minutes to hours.

Infection occurs in three main ways:

  • breathing in air that contains infectious particles
  • infectious particles landing on your mouth, nose or eyes (for example, through being coughed or sneezed on)
  • touching your mouth, nose or eyes when your hands have been contaminated by the virus, either through direct contamination, or indirectly by touching surfaces contaminated with the virus.

Current evidence shows the virus that causes COVID-19 (SARS-CoV-2) is spread by aerosols which is why air ventilation is important. Transmission from surfaces is the least common but it is still important to clean surfaces to reduce the risk. 

Read more about reducing the risk of COVID-19 through air ventilation.

Conditions that affect COVID-19 spread

A person is most infectious and more likely to spread the virus in the few days around the time that symptoms develop. This means that some individuals can be contagious before they develop symptoms.

The risk of becoming infected increases the closer you are to a person and the longer you are close to that person, especially if this contact occurs in poorly ventilated indoor spaces.

Most large droplets will fall to the ground within 2 metres. However, in some situations the virus has been transmitted to people more than 2 metres away, or to people who passed through a space soon after the infectious person left.

Things that increase the risk of this ‘long-range’ infection include:

  • being in enclosed spaces with poor ventilation within which fine particles containing virus can build-up
  • being near an infected person breathing heavily (for example, due to exercise, singing or shouting)
  • being exposed to these conditions for a longer period of time.

The ‘Three Cs’ are situations where spread of the virus is most likely are:

  1. closed spaces with poor ventilation
  2. crowded places with many people nearby
  3. close-contact settings, especially where people have close-range conversations, singing or shouting.

The risk is highest when these factors overlap: for example, in small, poorly ventilated spaces with lots of people talking loudly or shouting. The risk is lower outside, with fewer people, if they are widely spread.

Infection and immunity

People are considered likely to be infectious from 48 hours before the onset of symptoms. To prevent the spread of the virus people who have tested positive are required to isolate for full 7 days. Day 0 is from symptom onset, or day test taken, whichever came first.

Some people who have the virus may not have any symptoms (asymptomatic cases) and could still be infectious. Some people may test positive for COVID-19 after they have recovered and no longer have symptoms, but they are unlikely to be infectious beyond 24 hours after their symptoms have ended.

Once a person is infected with COVID-19, their body will usually produce cells (antibodies) that ‘remember’ the virus. We assume these antibodies give the person immunity from the virus.

Read more on infection and immunity

Getting vaccinated

The COVID-19 vaccine is free, voluntary and available to everyone in New Zealand aged 5 and over.

Vaccination means that if you do become infected you are far less likely to fall seriously ill or require hospital care.

While two doses provide some degree of protection against severe disease from Omicron, a booster is likely to offer greater protection. Anyone 18 and over can receive a booster shot at least three months after their second vaccination. People aged 16 or 17 can get a COVID-19 booster six months after completing their primary course.

A second booster is recommended for those at increased risk of severe illness from COVID-19 – a minimum of 6 months after a first booster

Reserve your spot today at Book My Vaccine.nz and if you have questions or need help booking, call the COVID Vaccination Healthline 0800 28 29 26.

Read more about getting a COVID-19 vaccination.


COVID-19 infections cause two major issues. The first is the viral attack on the body and the harm that causes, the second is that in some cases the virus also triggers an immune reaction which again can also cause harm.

New treatments being studied now cover both these areas and concentrate on three areas:

  • Antiviral drugs limiting the ability of the virus to thrive in the body. An example here is Remdesivir which is in use in New Zealand. 
  • Medicines that calm the immune system over-reaction prompted in some patients. An example here is dexamethasone which has been a standard part of our treatment protocols for some time.
  • Antibody treatments that help the body fight the virus.

There are medicines now available for COVID-19 that can be prescribed for those in the community who have a higher risk of severe illness and hospitalisation.

Read more about COVID-19 medicines.

People at higher risk of severe illness

Older people and people with some existing health conditions have a higher risk of more severe illness if they contract COVID-19. You may be more vulnerable if you:

  • have a high risk medical condition and/or compromised immunity
  • are over 65 years old, particularly if you have a medical condition
  • live in an aged care facility
  • are pregnant
  • have a disability
  • live with mental health conditions and addictions
  • are of Māori or Pacific ethnicity.

Read more advice for COVID-19 and higher risk people.


There is increasing evidence emerging on the long-term health impacts of COVID-19 (long COVID). 

Most people with COVID-19 recover completely and return to normal health. People usually recover from COVID-19 after 2–6 weeks and many make a full recovery within 12 weeks.

For some people signs and symptoms can carry on for longer than 12 weeks, may change over time, and new symptoms may develop. In addition, some patients develop medical complications that may have lasting health effects. 

Read more about Long COVID.

How to protect yourself and others

To protect yourself and others it’s important to: 

Read more about how to protect yourself and others and visit the Unite Against COVID-19 website.

In this section

  • The latest information about when people with COVID-19 are likely to be infectious, and their immunity afterwards.  Read more
  • Advice and information on long COVID for the general public Read more
  • The SARS-CoV-2 virus that causes COVID-19 has undergone genetic mutations over time leading to the development of new variants of the virus. Find out about variants, including Delta, Omicron, and the COVID-19 Variants of Concern framework Read more
  • The latest evidence shows that getting reinfected with COVID-19 can occur within a short period of time. Reinfection will become more likely as new variants spread among the community. Read more
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