A prominent doctor says the flu season could be particularly bad this year because the country has far lower natural immunity.
College of General Practitioners medical director and Porirua GP Dr Bryan Betty told Morning Report the influenza virus had barely been in New Zealand for two years, because of the closed border.
"The thing we need to understand about the flu - it's brought in from overseas by aeroplanes."
He said the flu was not a mild illness - about 500 people die of it in New Zealand in a normal year.
"New Zealand I think is particularly vulnerable because our borders were so closed we actually had no flu essentially in the country the last two seasons. As a result of that we think our natural immunity is down, which means we're far more susceptible to a bad flu season this year than perhaps we normally would be."
Betty said it was especially important for older, younger and immunocompromised people to get their vaccinations, which were available from today.
"If you're European over the age of 65, Māori and Pacific from the ages of 55 are eligible for a free vaccination, then anyone who is essentially living with a chronic disease be it diabetes, maybe rheumatoid arthritis, asthma, some sort of condition that is chronic and ongoing.
"The other group to really highlight this year is children. Children can be very badly affected by the flu, especially children over the age of 3 living with conditions such as asthma or respiratory conditions or underlying health conditions such as Type 1 diabetes."
The flu vaccination was completely different to the Covid-19 vaccinations, he said.
He said the flu vaccine was safe, effective and one we have had for years.
There was no doubt you could get some minor side effects from the flu vaccination, such as slight cold-like symptoms, as the immune system clocked up but getting the flu was a far worse outcome, he said.
"The flu vaccination reduces severity, again it reduces [risk of] death."
Masking was something to think about to reduce the spread of the flu too, he said.