COVID-19 vaccine third dose for severely immunocompromised people

Everyone in Aotearoa New Zealand aged 12 years and over can get the COVID-19 vaccine given as 2 doses, 3 to 6 weeks apart. However, people with compromised (weakened) immune systems are advised to get an additional third dose of the vaccine.

On this page you will find information about:

Who needs an additional third dose of COVID-19 vaccine?

Currently, the Ministry of Health, NZ is recommending that moderately to severely immunocompromised people receive an additional dose. This includes people who have:

  • been receiving active cancer treatment for tumors or cancers of the blood
  • received an organ transplant and are taking medicine to suppress the immune system
  • received a stem cell transplant within the last 2 years or are taking medicine to suppress the immune system
  • advanced or untreated HIV infection
  • active treatment with high-dose corticosteroids or other medicine that may suppress your immune response.

Talk to your healthcare provider about your medical condition, and whether getting an additional third vaccine dose is appropriate for you.

Why is an additional third dose recommended?

People with moderately to severely compromised immune systems are especially vulnerable to COVID-19, because:

  • Having a weakened immune system means that you may not build the same level of immunity to two doses of the vaccine, to adequately protect you against COVID-19.
  • They are at higher risk of severe complications from COVID-19 compared to non-immunocompromised people.
  • They tend to have a prolonged infection and viral shedding period, are at higher risk of developing a new variant, and are more likely to transmit the virus to any contacts compared to non-immunocompromised people.

The additional vaccine dose is intended to improve immunocompromised people’s response to their initial two dose of the vaccine.

How long after getting my initial COVID-19 vaccines can I get my third dose?

The Ministry of Health recommends the additional dose of the Pfizer COVID-19 vaccine be administered more than eight weeks after the second dose.

When considering the timing of your third dose, your doctor will also pay special attention to whether you are currently receiving or planning to get immunosuppressive therapies.

Where possible, the third dose will be delayed until two weeks after the period of immunosuppression, in addition to the time for clearance of the therapeutic agent. 

What are the risks of having a third vaccine dose?

There is limited information about the risks of receiving an additional dose of vaccine, and the safety, efficacy, and benefit of additional doses of COVID-19 vaccine in immunocompromised people continues to be evaluated.

So far, reactions reported after the third vaccine are similar to that of the second dose: tiredness and pain at injection site were the most commonly reported side effects, and overall, most symptoms were mild to moderate. As with the first and second dose, serious side effects are rare, but may occur. Read more about the Pfizer vaccine.

How and where can I get a third dose of the COVID vaccine?

  • If you are immunocompromised (have a weakened immune system), you can contact your GP or specialist to check if you are eligible to receive a third dose of the vaccine. Alternatively, your GP may contact you to let you know you are eligible.
  • You will then have to go to see your GP to collect a prescription for the third dose and sign a consent form. This consultation will be at no cost to you.  
  • if your GP practice is set up to give the COVID vaccine, then you can get the vaccine there. However, if your GP practice does not give the COVID vaccine, you can take the necessary documentation to the nearest vaccination centre, to get your dose.  

What is the difference between an additional dose and a booster shot?

An additional dose is administered to people with moderately to severely compromised immune systems. This additional dose of the COVID-19 vaccine is intended to improve an immunocompromised person's response to their initial vaccine series. A booster shot is administered when a person has received their first and second dose, and protection against the virus has decreased over time.

If I am immunocompromised do I need an additional dose and a booster shot?

At this time, the Ministry of Health does not have a recommendation for immunocompromised people to receive both a booster shot and an additional dose. The current recommendation is for immunocompromised people to receive an additional dose more than eight week after completing the second COVID vaccine.  


  1. Third primary dose of the Pfizer/BioNTech vaccine policy statement and clinical guidance Ministry of Health, New Zealand
  2. COVID-19 vaccine: severely immunocompromised people Ministry of Health, New Zealand
Credits: Health Navigator Editorial team. Last reviewed: 04 Nov 2021