A leading virologist says almost a third of the population contracted swine flu last year and warns many people will be susceptible to the virus this winter.
While he expects this winter's outbreak to be milder, Dr Lance Jennings says it's no time for complacency.
Dr Jennings says it's important those considered at risk, such as the elderly, get vaccinated, and basic respiratory hygiene practices are followed.
He says hygiene is particularly important in schools as children easily share germs.
The Ministry of Health says 35 people died from swine flu last year.