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.

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

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™.

​In November 2014, the Pharmacovigilance Centre of Netherlands (Lareb) provided an updated overview of Dutch cases of narcolepsy reported to have a link to Pandemrix.