Seroprevalence of the 2009 influenza A (H1N1) pandemic in New Zealand
A new scientific study shows the full effect of Pandemic Influenza H1N1 in New Zealand in 2009
The Ministry commissioned study, conducted by Environmental Science and Research (ESR), estimates that 1.26 million or 29% of New Zealanders were immune to the pandemic influenza virus by March this year.
About 480,000 people had some immunity prior to last year’s pandemic wave, mostly in the older age groups. An additional 780,000 were estimated to have been infected during 2009. The highest rate of infection during 2009 was in school age children - where one in three children were affected. Almost half of those infected showed no obvious symptoms.