Doctors are urging people to get flu vaccinations before the Easter holidays.
The flu virus could be spread by people getting together during the school holidays, the National Influenza Specialist Group (NISG) has warned.
Virus expert and NISG spokesman Dr Lance Jennings said it was important people were immunised before the school holidays.
Dr Jennings said the A(H1N1) virus strain was increasing in Queensland - a popular destination for families at this time of year.
"This particular virus can lead to serious complications for younger, previously healthy people, but the good news is it is covered by the 2014 vaccine,'' he said.
The 2014 seasonal influenza vaccines for New Zealand include two new World Health Organisation-recommended strains based on those most likely to spread and cause illness in people this season.
The flu vaccine is free for New Zealanders over 65, anyone with long-term health conditions, pregnant women and children aged 6 months to 5 years with respiratory problems.