A team of scientists have associated an influenza vaccination - Pandemrix - to an increased risk of narcolepsy in young adults.
Using a population-based prospective cohort study, the team analyzed data from regional vaccination registries and national health registries, covering seven healthcare regions and 61 percent of the Swedish population.
While the team did not identify any link to a large number of immune-related or neurological diseases, they did confirm an increased risk in diagnosis of narcolepsy in individuals younger than 20 years of age, and observed a trend towards an increased risk amongst young adults between 21 and 30.
Dr. I. Persson from the Karolinska Institutet, Stockholm, said that the follow-up of Pandemrix vaccinations in a large registry based study in Sweden confirms an increased risk of narcolepsy in children and adolescents, while also providing reassuring results for a large number of other neurological and immune related diseases.