COVID-19 vaccines

For comprehensive, accessible information and the latest updates on COVID-19 vaccines generally, we recommend the three resources below. Alternatively, scroll down to find links related to specific questions or areas of interest.

How do vaccines work?

This article from the World Health Organization (WHO) explains how vaccines work with the immune system to protect us from pathogens, and why it is important to vaccinate lots of people within a community.

Read the WHO article ‘How do vaccines work?’

The short video above from Nature explains how vaccines train the immune system to protect us from disease, outlines the role of herd immunity, and describes different approaches to vaccine design.

A gif describing the three main strategies for making a vaccine.

The above graphics by Toby Morris accompany an article by Dr Siouxsie Wiles that explains the different approaches to vaccine design.

Read the article ‘The race for a COVID-19 vaccine, explained’ on The Spinoff

Aotearoa New Zealand’s vaccine portfolio

​New Zealand has access arrangements for four COVID-19 vaccines, all of which have been provisionally approved by Medsafe:

  • Pfizer/BioNTech – this mRNA vaccine has been the main COVID-19 vaccine used in New Zealand so far
  • AstraZeneca – while Pfizer is the preferred vaccine for use in New Zealand, this viral vector vaccine is available for people who want a different option
  • Janssen – this viral vector vaccine isn’t currently available for use in New Zealand
  • Novavax – this protein vaccine is available for use in New Zealand, although it isn’t approved for use as a booster at this time

We have such a range of vaccine options because purchasing decisions were made before any vaccine had been proven to be safe and effective. This was a necessary investment decision to ensure timely vaccine access for all New Zealanders and for our Pacific neighbours.  New Zealand is also a Covax member, supporting vaccine access in developing countries and expanding our own vaccine options through this international vaccine access arrangement.

See the Ministry of Health’s webpage for more information on New Zealand’s vaccine portfolio.


The Pfizer/BioNTech vaccine is RNA-based. It is the main vaccine being rolled out in New Zealand.

How the Pfizer vaccine for COVID-19 works – article by Dr Siouxsie Wiles and Toby Morris for The Spinoff

Nucleic acid vaccines – explainer from Gavi

RNA vaccines – infographic and explainer from Compound Interest

Pfizer vaccine explainer by the Immunisation Advisory Centre.

Watch Dr Ian Town explain how the mRNA vaccine works.

AstraZeneca and Janssen

Both the Janssen and AstraZeneca vaccines use a non-replicating viral vector approach.

Viral vector vaccines – explainer from Gavi

Viral vector vaccines – infographic and explainer from Compound Interest


The Novavax vaccine uses a protein subunit approach.

Protein subunit vaccines – explainer from Gavi

Aotearoa New Zealand’s vaccine roll-out

COVID-19 vaccines are available free of charge in Aotearoa New Zealand. To find out how to get your COVID-19 vaccination, including your booster, visit the government’s official COVID-19 website. To get proof of your vaccine status, visit the Ministry of Health’s vaccination record website.

Data on vaccine coverage in Aotearoa New Zealand can be found on the Ministry of Health’s website.

Vaccine safety

This explainer from WHO breaks down the different ingredients found in vaccines and steps the reader through the clinical trial process.

Read the WHO article ‘How are vaccines developed?’

In Aotearoa New Zealand, a vaccine must be approved by Medsafe before it can be rolled out. Medsafe examines all available data to determine if a vaccine meets international and local requirements for safety, efficacy and quality. Read more at the links below. 

Read about ‘Vaccine safety and approval’ from the Ministry of Health

‘Making sure COVID-19 vaccines are safe and effective’ – Unite against COVID-19

Learn about the Vaccine Safety Monitoring Process from Medsafe

The Immunisation Advisory Centre has made a video on vaccine safety. The video is also available in Te Reo Māori.

Dr Ashley Bloomfield and MedSafe Group Manager Chris James explain how vaccine approval works in New Zealand.

Vaccine equity

Aotearoa New Zealand’s vaccine strategy includes supporting equitable vaccine access internationally, and in particular helping our Pacific neighbours. This is the right thing to do, and will also help to reduce the emergence of new variants – we’re not safe until everyone is safe.

Our World in Data collates information on global COVID-19 vaccine coverage. Their world map showing the percentage of a country’s population that has received at least one COVID-19 vaccine dose reveals stark global disparities, with countries in the African continent in particular having very low vaccine coverage.

What about new variants?

Every time the virus makes a copy of itself, changes can be introduced into its genetic code. The accumulation of changes over time can lead to the emergence of new variants of the virus, which may have different properties.

WHO keeps track of variants of concern, paying particular attention to whether new variants are more transmissible, cause more severe disease, or are less able to be managed using existing vaccines, diagnostics or therapeutics. WHO has so far identified five variants of concern, including the Delta and Omicron variants. Both of these variants are more transmissible than the original version of the virus, and vaccine efficacy against Omicron is lower than for other variants, but is substantially increased if a person has a third (booster) dose.

The Ministry of Health regularly publishes updated information on variants.

The COVID-19 vaccine landscape

Beyond the four vaccines in New Zealand’s COVID-19 vaccine portfolio, there are hundreds more in various stages of development, including over 20 that are being used in other countries.

The London School of Hygiene and Tropical Medicine and New York Times  maintain COVID-19 vaccine development trackers, and the World Health Organization maintains a list of vaccines that it has endorsed or is currently evaluating.

The four main vaccine types as explained by Gavi, the Vaccine Alliance.