Health authorities are warning New Zealand could be hit this winter by a virulent "Brisbane strain" of flu which killed six children in Australia last year.
Furthermore, New Zealanders could prove more vulnerable to the virus this year due to low immunisation rates and several mild flu seasons.
Virologist Lance Jennings told the New Zealand Doctor magazine the country was due for a serious influenza season after a lull lasting several years.
The last serious season - in 2005 - saw three children die from an influenza "B" strain.
National Influenza Strategy Group chair Anne-Marie Frost said this year's vaccine included three strains.
One, dubbed the "Brisbane strain" had killed six children in Australia last winter. European authorities have warned the strain could be the most deadly they have seen in 20 years.
"The ingredients are all there for an influenza season much worse than we've seen before, or for a long time," she told the magazine.
"It's a bit of a bonfire ready to go."
This year's vaccination also contains an H1N1 strain - a variant of which caused the 1918 flu epidemic - and a "B" strain.