A vaccinologist says people are unlikely to need an annual booster of the Pfizer vaccine.
Helen Petousis-Harris told Breakfast the response to Covid-19 is not the same as that of influenza, where a dose is needed every year.
"I think we should think of it more like the vaccines that we give routinely, say to kids or adults, where you have one or two doses and then a booster," Petousis-Harris, an associate professor at the University of Auckland said.
"I think this is really how we should look at this one."
Petousis-Harris' comments come after the Government announced on Monday boosters will be rolled out from November 29.
Those aged over 18 who have been fully vaccinated for at least six months will be able to get a booster.
"Our healthcare and border workers are a priority group for booster vaccine doses because they’re on the front line against Covid-19 and because large numbers of them completed their vaccine course six months or longer ago," Covid-19 Response Minister Chris Hipkins said.
"We will also be making sure older people including people in residential care have good access to booster doses when they become eligible."
Petousis-Harris said the booster would "complete the course, if you like".
"I’m not seeing a situation where we’re likely to need annual doses. I think that’s going to be more about if we get some really inconvenient variants popping up."
If this occurred, she said: "Ideally it would be about re-formulating the vaccine to match and I don’t think we’re going to see that kind of happen like flu does."
Petousis-Harris felt the time-frame for a booster could be longer than six months.
"Six months isn’t a time you suddenly magically can’t fight this disease off. Six months is a time where you’re circulating antibodies are kind of waning, but you’ve got a lot more in your artillery available to be able to fight that off, which is why people aren’t getting really very sick once they get out past six months. They’re more likely to get infected," she said.
“You’re going to be better off after your booster than you were after your second dose.”