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 Tuesday.
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 to those who were not vaccinated in the same age group, it said.
The agency said, however, that the increase likely 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.