A third dose of the Pfizer Covid-19 vaccine recommended for the severely immunocompromised is now available.
Health experts had recommended this , Director-General of Health Dr Ashley Bloomfield said on Tuesday.
The dose is different to a booster shot for the general population.
"Severely immunocompromised people are at high risk of severe outcomes of Covid-19 ... and may not produce a sufficiently strong immune response to just two doses," Bloomfield said.
That includes those aged 12 and older who are severely immunocompromised New Zealanders, such as those who have had transplants or those with chronic diseases.
Jo Gibbs, national director of the Covid-19 vaccination and immunisation programme, said the third primary dose can be administered at least eight weeks after the second dose.
"Providing an optional third primary dose to individuals with severe immunosuppression will help protect our most vulnerable against severe disease and hospitalisation if they were to contract Covid-19.
"Everyone aged 12 and older who is a household or close contact of someone who is immunocompromised is strongly encouraged to receive two doses of the Pfizer vaccine. This will help provide indirect protection to the most vulnerable people in our communities."
"The eligibility criteria to access a third primary dose is complex and applies to only the group of people who are severely immunocompromised," she said.
"Individuals who meet the eligibility criteria will need to be prescribed a third dose by their GP or other specialist and present the script when accessing the third primary dose."
Eligibility criteria to access the third dose can be found on the Ministry of Health's website .
A recommendation on whether a booster should be offered to the general population will be made in the coming months, Gibbs said.
"Cabinet will make a final decision on whether the general public will be able to access a booster vaccine, following Medsafe’s assessment once it receives additional data from Pfizer."