Pandemrix is an influenza vaccination, created in 2009 to combat H1N1, known as Swine Flu. Now, a team of Swedish clinicians testing the vaccine for links to immune-related or neurological diseases have linked 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% 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.
"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," said Dr. I. Persson from the Karolinska Institutet, Stockholm.
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I. Persson, F. Granath, J. Askling, J. F. Ludvigsson, T. Olsson, N. Feltelius, 'Risks of neurological and immune-related diseases, including narcolepsy, after vaccination with Pandemrix: a population- and registry-based cohort study with over 2 years of follow-up', Journal of Internal Medicine, DOI: 10.1111/joim.1215