Almost half the students at a Marlborough primary school have been struck down by swine flu in the area's first confirmed outbreak this year.
Students at Seddon School were tested for the H1N1 virus after complaining of sore throats, coughing and fevers.
The outbreak is now slowing, but at one point 46 of the school's 107 children were sick.
The Nelson Marlborough Medical Officer of Health, Doctor Ed Kiddle, says swine flu will be the most common strain of influenza this winter.
He says vaccination is very important, especially for people with other medical conditions.
Last year, 35 people died of swine flu. Almost a third of New Zealanders contracted the virus.