Booster doses help build up immunity which can weaken over time. Antibody levels wane for most adults over time, although the level of antibody needed to protect against infection is a lot higher than needed to protect against severe disease if infected. For COVID-19, protection against any infection, especially infection with minimal or no symptoms, wanes relatively quickly (within a few months), but protection against severe disease lasts much longer, even against delta and omicron variants. Booster doses can assist to build protection back up.

First boosters are available for all those over 18 years who finished their primary course at least 3 months ago, and for 16-17-year-olds who finished their primary course at least 6 months ago.

Second boosters are only recommended for those at increased risk of severe illness from COVID-19, and from a minimum of 6 months after a first booster. See section further down for details on second boosters.

Vaccines to use as a boosters

  • Comirnaty mRNA-CV vaccine is the preferred booster vaccine in Aotearoa New Zealand and can be used for people over 16 years without prescription for boosters 1 and 2.
  • Novavax's Nuvaxovid vaccine can be used as a first or second booster without a prescription, for people over 18 years.
  • More information about which COVID-19 vaccines are available for use in New Zealand as either primary course or booster is here.   

First booster doses are particularly important for:

First boosters are recommended for everyone over 18 years, and for those at risk from 16 years. They are particularly important for:

  • highly vulnerable people such as the frail elderly or those with significant comorbidities.
  • people with continued occupational exposure to SARS-CoV-2 and/or caring for people with COVID-19 disease, such as health care and border workers. They are more likely to be exposed to SARS-CoV-2 infection and have a higher potential to transmit the infection to people at risk of severe disease. (These are not priority groups for second boosters though.)
  • those living in households with people with immunocompromise. 

First booster doses for immunocompromised

A booster dose for immunocompromised can be given anytime from 3 months (ideally 6 months) after they have had their third primary dose. More on vaccination for those with immunocompromise issues can be found here, and information on extra doses and booster doses for those with immunocompromise here

Second COVID-19 boosters 

Second boosters for those at risk of severe illness from COVID-19

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. This 6 month gap allows the immune response to mature to provide optimal and sustained protection. 

For those who are not considered at risk of severe illness from COVID-19, a two-dose primary course and a single booster dose provides very good protection against severe illness from COVID-19.

A second booster is currently not considered necessary for those who are younger or healthy, including those who are pregnant unless they are in the groups recommended below.

The following people are recommended to receive a second booster as a priority and should be actively recalled for their vaccine dose if possible: 

  • people aged 65 years and over
  • Māori and Pacific peoples aged 50 years and over
  • residents of aged care and disability care facilities
  • severely immunocompromised people who received a three-dose primary course and a fourth dose as a first booster (noting this would be a fifth dose for these people)
  • people aged 16 years and over who have a medical condition that increases the risk of severe breakthrough COVID-19 illness and
  • people aged 16 years and over who live with disability with significant or complex health needs or multiple comorbidities.

Clinical criteria in support of second booster eligibility

In addition, a second booster is available for (no recall needed)

  • Māori and Pacific peoples aged 40 years and over
  • all people aged 50 years and over
  • health, aged care, and disability workers aged 30 years and over.

Second COVID-19 boosters and healthcare workers 

If your workplace is using effective infection control measures you are more likely to be infected with SARS CoV-2 outside of the workplace. Numerous studies support this.  

Continue to protect yourself, your patients and your colleagues by staying home if symptomatic or infected, wearing well-fitting masks and following testing protocols. 

The first booster dose remains the most important single step to protect against Omicron – it strengthens protection against symptomatic infection for a few months and for at least 6 months against severe disease. 

A second booster is not expected to provide that much additional benefit to healthy individuals, but is recommended for those at risk of severe illness from COVID-19 infection. 

If you are in a priority group, consider a second booster, otherwise it is not recommended at this time.

A summary of evidence is available.

IMAC links for further information

Boosters for adolescents fact sheet

Research on second boosters 

Ministry of Health policy link

Booster vaccination policy statement 

Last updated: 16 March 2023