How COVID-19 vaccines protect you

The COVID-19 vaccine stimulates your body’s immune system to make antibodies and fight the virus.

The vaccines help prevent you from:

  • getting infected
  • having COVID-19 symptoms
  • severe illness.

This means you could have COVID-19 with no symptoms or will have fewer, milder symptoms and recover faster.

Being up to date with your immunisations means that you might still get infected with COVID-19. But it significantly reduces your chances of becoming seriously ill or ending up in hospital.


Vaccine safety

COVID-19 vaccines are one of the most well-studied vaccines ever made.

They needed to be rolled out quickly, but that does not mean safety was compromised. The Pfizer vaccine we are using in Aotearoa New Zealand is held to the same high safety standards as any other medicine.

How does the vaccine work

Pfizer vaccines

The COVID-19 vaccine we use in Aotearoa New Zealand is made by Pfizer-BioNTech.

It is also known by its brand name, Comirnaty. It is an mRNA-based (messenger ribonucleic acid) vaccine.

The vaccine used is updated according to the strain of COVID-19 circulating in the community at the time.

You should not get the Pfizer vaccine if you have had a severe allergic reaction to this vaccine or its ingredients. Talk to your vaccinator or healthcare provider about your options.

Pfizer paediatric

Pfizer paediatric (child) is a vaccine that contains a lower dose of mRNA vaccine. It is:

  • for tamariki aged 5 years to 11 years old
  • infants aged 6 months to 4 years who are at higher risk of severe disease from COVID-19.

How the Pfizer vaccine works

The Pfizer vaccine (Comirnaty) is an mRNA vaccine that contains the genetic code for an important part of the SARS-CoV-2 (COVID-19) virus called the ‘spike protein’. Spike proteins are the little projections on the surface of the virus.

  1. Once you have had the vaccine, your body reads the genetic code and makes copies of the spike protein.
  2. Your immune system detects these spike proteins and learns how to recognise and fight against COVID-19. It knows it needs to attack the virus to protect it from spreading in your body.

The genetic code is used by the immune system for as long as it needs it. After that it is broken down by the lymph nodes. This usually takes a few days. In some cases, it can take up to 2 months. 

The Pfizer vaccine cannot give you COVID-19

The Pfizer vaccine cannot give you COVID-19. mRNA vaccines do not contain any of the virus that causes COVID-19, or any other live, dead or deactivated viruses. There are no animal products in this vaccine.

The Pfizer vaccines does not affect your DNA

The Pfizer vaccine does not affect your DNA It does not affect or interact with your DNA or genes. mRNA vaccines never enter the nucleus of the cell which is where our DNA is kept.

Novavax vaccines

The Pfizer vaccines are the only Medsafe-approved and funded vaccines that are available for use in Aotearoa New Zealand. Pharmac have previously funded a Novavax vaccine for COVID-19. However, in July 2024 Novavax decided to withdraw its application for approval of its latest vaccine, Nuvaxovid XBB.1.5 vaccine. Therefore, the Novavax vaccine is currently unavailable in Aotearoa New Zealand.

If you have any questions or would like to discuss your options, talk to your healthcare provider or call the Vaccination Helpline on 0800 28 29 26


How vaccines are approved for use in Aotearoa

Medsafe is Aotearoa New Zealand’s medicines safety authority. It checks applications for all new medicines, including vaccines, to make sure they meet international standards and local requirements.

It will only recommend approving a medicine for use in Aotearoa if it meets these standards.

Medsafe focuses on 3 key areas when assessing a vaccine:

  • safety
  • efficacy
  • quality.

Its assessment includes looking at:

If the vaccines contain new organisms

If any of the COVID-19 vaccines arriving into Aotearoa contain a new organism, the Environmental Protection Authority (EPA) will be involved.

New organisms — Environmental Protection Agency (external link)


Vaccine side effects

As with all medicines, you might experience some mild side effects when you get a COVID-19 vaccination. This is common, and a sign that your body is learning to fight the virus.

COVID-19 vaccine side effects and reactions (internal link)