Kiwis are being urged to get the flu jab as health authorities see a sudden jump in cases of the dreaded lurgy.
Doctors in Waikato are reporting a sudden increase in influenza-like illness and corresponding influenza A cases in the region.
Dr Anita Bell, Waikato District Health Board's medical officer of health, says the flu season is well under way, with a number of clinics and hospitals treating people for flu-type illnesses and respiratory infections.
"The only way to protect yourself and your loved ones is to get vaccinated," Dr Bell said.
The vaccine is only available until July 31 and is free for those most at risk of complications from flu.
Influenza is a potentially serious viral infection with symptoms that are usually much more severe than a cold.
It affects up to one in five New Zealanders every year, with 400 deaths annually related to influenza infection.
Those who believe they may have the flu should stay at home, cover their cough or sneeze using disposable tissues, regularly wash their hands with soap and hot water and dry them thoroughly.