HELSINKI — Finnish researchers have found an increased risk of narcolepsy among 4- to 19-year-olds who were given swine flu shots, a government health agency said yesterday.
A preliminary study by the National Narcolepsy Task Force indicates that children vaccinated with Pandemrix “contributed to the observed increase in incidence of narcolepsy’’ compared with those not vaccinated in the same age group, it said.
The agency said, however, that the increase probably was caused “by joint effect of the vaccine and some other factor,’’ and added that it would have to conduct more research, as similar increases in narcolepsy cases have not been reported in other countries using the vaccine.
Pandemrix shots were made for the swine flu pandemic, and it is not clear whether they are still being given, because the usual flu shot now includes the swine flu strain. In Finland, health personnel stopped administering Pandemrix in August 2010 when concerns were first voiced about the vaccine.
Narcolepsy is a rare disorder that causes people to suddenly fall asleep. It is seldom fatal.
The National Institute for Health and Welfare, which published the findings, said that 60 children and adolescents contracted narcolepsy in Finland in 2009 and 2010. Fifty-two of them — or almost 90 percent — had received the Pandemrix vaccine.
The study found that the biggest increase was among those age 5 to 15 years.