More than 140,000 people have already had their Covid-19 booster shots.
Photo: RNZ / Nate McKinnon
Boosters have been available for eligible people for less than two weeks.
Anyone aged 18 or over, who has been fully vaccinated for at least six months, is able to get one.
This week, about 9000 boosters have been given each day.
The Ministry of Health website says that currently booster doses will not be mandatory for workers who are required to be vaccinated nor to get a vaccine certificate.
A study has shown the booster shot provides a similar level of protection against new variant Omicron as two doses against other variants.
Last week, Covid-19 Response Minister Chris Hipkins told Morning Report that the government's technical advisory group is considering whether to shorten the time frame between the second and third dose of the Pfizer vaccine.
The Ministry of Health expects 455,847 people to be eligible for a booster shot by the end of the year.
Meanwhile, close to 20,000 people have had a third primary dose of the vaccine.
This is different to a booster and is prescribed to people who are severely immunocompromised.
The Health Ministry says these people may not get a sufficiently strong immune response after two doses, so a third can be beneficial.