A preliminary investigation by Sweden’s Medical Products Agency of a putative link between GlaxoSmithKline’s Pandemrix pandemic H1N1 vaccine and a handful of cases of narcolepsy – a rare sleeping disorder — has found no evidence of a link. In an update reported 10 September, it says that study of the 22 cases reported from October 2009 to August 2010, shows than any increase in incidence “seems to be of the same magnitude in those vaccinated as in those not receiving any vaccine.”
Twenty of the cases occurred in those younger than 18 years old, whereas normally about 10 cases annually are reported in Sweden in this group, suggesting an increase – though the Swedish agency notes that the numbers are so small that caution is needed in affirming any change from baseline levels.
The European Medicines Agency also launched a review of any link to the vaccine in August following reports of a handful of cases of narcolepsy in Sweden and Finland that occurred shortly after vaccination. Finland has suspended use of the vaccine pending its own inquiry.