Whanganui District Health is urging people to get vaccinated against the flu.
WDHB's infection prevention and control clinical nurse specialist Jacqueline Pennefather said the flu doesn't disappear in spring.
"As we've seen this year, many people have had the flu and some have been very unwell. I would urge people to do everything they can to avoid it."
The flu vaccine was available until New Year's Eve, Mrs Pennefather said.
Some people qualify for a free flu vaccination, including pregnant women, anyone aged over 65, or anyone with a chronic condition such as respiratory or heart disease. Children living in an earthquake-affected area (such as Christchurch or Kaikoura) also qualify.