From today, more people are eligible for the Covid-19 bivalent vaccine, which protects against two strains of coronavirus.
Chris Hipkins got his injections at a community vaccination event in Upper Hutt on Saturday morning, alongside Health Minister Ayesha Verrall.
He said it was important eligible people got the jabs before winter arrived.
"It will actually leave them better prepared for the winter season, help to ease pressure on the health system as well.
"So there'll be more events like this happening around the country where our local community health providers will be encouraging people to get their flu jabs and their Covid boosters and I'd really encourage people to take up that opportunity."
There were currently more than 700,000 Covid vaccines and 800,000 flu jabs in the country, with more due to arrive, she said.
The government had ordered more flu vaccines than last year, she said.
"We have 1.7 million Covid bivalent vaccines and Pharmac has 1.8 million flu vaccines, last year we needed 1.2 million flu so we've got a margin there that we're able to do more cause we hope we will be able to reach more people this year."
A combination of Covid and flu added to the strain on New Zealand's hospitals last year and people should get the flu vaccine and Covid booster to try and help avoid that this year, she said.
Doctor Andrew Narayan from Queen Street Medical said it was a privilege to administer the vaccines.
"But again you know, at the end of the day another human being protected against the virus, hopefully we all can take lessons from it and you know if he [Chris Hipkins] can do it then there should be no reason why anybody else can't do it."
Dr Narayan said the aim was to administer at least 800 jabs by the end of the day.
Dr Verrall said all New Zealanders aged over 30 could now access the Covid booster, so long as it had been at least six months since their last Covid-19 booster or positive Covid test.
People at higher risk of severe illness from Covid-19 would also be able to receive an additional booster, regardless of how many doses they had had previously, she said.
The Covid booster is free of charge for people aged 65 and over, Māori and Pacific people aged 50 and over, pregnant people and those most likely to get very sick with the flu.
The flu vaccine is free for people aged 65 years and over, Māori and Pacific people aged 55 years and over, pregnant people, and people who have long-term conditions like diabetes, asthma, or heart conditions, children aged six months to 12 years old, and people with mental health and addiction issues.
Many New Zealand workplaces also fund a free flu vaccine for their employees.