COVID-19 is a disease caused by the coronavirus SARS-CoV-2. It affects your lungs, airways and other organs.
Coronaviruses are a large and diverse family of viruses that cause illnesses such as the common cold. Other recent diseases caused by coronaviruses include severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS).
SARS-CoV-2 was first recognised in China and likely originated in animals. It is still unclear how the virus came to infect humans. The disease spread to other countries, with the World Health Organization (WHO) declaring a pandemic on 11 March 2020.
The virus has since undergone genetic mutations over time as it adapts to humans. Some of these mutations can spread more easily than the original virus.
Variants of COVID-19
It is a natural process for viruses to change or mutate, which may produce variants. Variants are developing around the world. This tends to happen in places where the virus is out of control.
WHO is tracking variants of concern and variants of interest.
Variants of COVID-19 may affect how fast the virus spreads, or how sick people get from the virus.
The Ministry of Health provides updates on variants and has a framework to prepare and respond to any new variants of concern.
Omicron was first classified as a variant of concern by WHO in November 2021. It has spread worldwide and is now the major variant in many countries.
Compared to Delta, Omicron:
- is more infectious
- causes similar symptoms, but because we have a highly vaccinated population, many people have milder or no symptoms (though could still pass the virus on to others)
- puts many more people in hospital, because Omicron can cause many more infections over a short period of time
- can still cause severe illness and even death, especially in people at high risk of serious illness, such as older people and people with underlying health conditions.
Omicron, like other variants, continues to change. Variants and sub-variants in New Zealand include:
- BA.2 — dominant in early 2022
- BA.2.12.1, BA.4 and BA.5 — first detected in New Zealand in late April 2022
- BA.2.75 — first detected in New Zealand in July 2022, may be slightly more infectious than BA.2.
Although new variants of Omicron continue to emerge, there does not appear to have been a change in the severity of COVID-19. New Zealand's public health settings to manage current Omicron variants are appropriate for its subvariants.
Detecting variants arriving in New Zealand
To identify which variant a person has, there needs to be whole-genome sequencing from a polymerase chain reaction (PCR) test.
We encourage people arriving from overseas to do rapid antigen tests (RATs). Those who test positive should have a follow-up PCR test to identify the variant.
How to protect yourself and others
Keep up healthy habits
Healthy habits can slow the spread of the virus and help protect you, your whānau, and your community from COVID-19. Healthy habits include handwashing and wearing a face mask in healthcare settings and crowded indoor places.
Getting vaccinated means if you have COVID-19, you are far less likely to:
- get very sick
- need to go to hospital
- infect other people.
While a 2-dose course provides some protection against severe disease from Omicron, this protection can decrease over time. Booster doses reduce the chance of serious illness and lower the risk of spreading COVID-19 to others.
The symptoms of COVID-19 are like common illnesses such as the cold or flu. Some people will only experience mild to moderate symptoms. Older people, ethnic minorities, and those with underlying medical conditions are at higher risk of severe illness from the virus.
Some people who have had the virus suffer health impacts longer than a few weeks or months. This is commonly referred to as Long COVID.
People at higher risk of serious illness can get antiviral medicines.
When taken early on in your COVID-19 illness, antivirals can help you get better faster and stay out of hospital.
Our response to COVID-19
New Zealand’s vaccine plan
High rates of vaccination is our main tool to protect people and minimise the spread of COVID-19. The COVID-19 vaccine is free and available to everyone in New Zealand aged 5 and over.
Wastewater testing helps monitor COVID-19 in New Zealand. It is a surveillance tool alongside testing community and border cases.
The Institute of Environmental Science and Research (ESR) tests wastewater around the country. An interactive dashboard shares ESR’s wastewater science. It can help you track potential COVID-19 risk in your area.
To monitor for new variants arriving from overseas, the Government uses:
- follow-up PCR (polymerase chain reaction) tests and genome sequencing of positive cases in travellers
- targeted surveillance at the border.
Last updated: at