ECDC has previously summarised information concerning the appearance of narcolepsy following the use of a specific pandemic vaccine (Pandemrix®) in children and adolescents in three European Countries.

Due to an association that was observed in the United States between a swine-flu based human influenza vaccine developed in 1976 and the disease acute polyneuropathy Guillain-Barré syndrome (GBS) (1,2), GBS was one of the adverse events that was monitored in Europe and North  America (3) following the 2009 influenza pandemic vaccination campaigns.

EMA recommends restricting use in persons under 20 years of age Pandemrix to be used only in the absence of seasonal trivalent influenza vaccines, following link to very rare cases of narcolepsy in young people. Overall benefit-risk remains positive.

​A pair of linked papers from Finland concerning the above topic, one epidemiological and the second combining both clinical and epidemiological were published on March 28th in the open access journal, PLoS One.(1,2).

Investigation of an increase in the incidence of narcolepsy in children and adolescents in 2009 and 2010 - Final Report of National Narcolepsy Study Steering Committee, Department of Health, Ireland

​In September 2010 Sweden and Finland noted a number of children had developed narcolepsy seemingly in association with having received the pandemic vaccine used almost exclusively in those countries (Pandemrix)

This is the first published study where an attempt has been made to understand the possible biological mechanisms behind development of narcolepsy following vaccination with Pandemrix™.