Upper airway infections the source of narcolepsy, not H1N1 vaccinations

Contrary to reports that narcolepsy resulted following H1N1 vaccinations in northern Europe and other areas, the onset of narcolepsy was highly correlated with seasonal and annual patterns of upper airway infections.
Self-reported data on the month and year of narcolepsy onset between September 1998 and February 2011 indicate that onset is most frequent in April and least frequent in November in China. Only eight out 142 narcolepsy patients reported having been vaccinated and 85 percent reported symptoms of upper airway infection, Internal Medicine News reports.
The findings show that the onset of narcolepsy in China is strongly seasonal and suggest that it is not related to H1N1 vaccination. While the occurrence of narcolepsy onset was over threefold greater than expected following the 2009-2010 H1N1 pandemic, 96 percent of new narcolepsy patients in 2010 did not report being vaccinated. This is in contrast with reports of narcolepsy in Canada, France, the United States and Finland following H1N1 vaccination with an adjuvanted vaccine, which caused alarm.
"Winter infections would initiate or reactivate an immune response that leads to hypocretin cell loss and narcolepsy in genetically susceptible individuals," the investigators wrote, according to Internal Medicine News.
Finding an association with infection and not vaccination is important because it suggest that limiting vaccination out of the fear of narcolepsy could actually increase overall risk, the authors wrote.