Adjuvanted flu vaccine associated with child narcolepsy in Finland

The authors of the studies, led by Markku Partinen of the Helsinki Sleep Clinic and Hanna Nohynek of the National Institute for Health and Welfare in Finland, found that the average annual incidence of narcolepsy between 2002 and 2009 among children younger than 17 was 0.31 per 100,000, and in 2010, this incidence was about 17 times higher, at 5.3 cases per 100,000. In contrast, the incidence rate for adults over 20 was essentially unchanged over that same time period.

To further evaluate the potential connection between the vaccine and narcolepsy, the researchers collected vaccination and childhood narcolepsy data for children born between January 1991 and December 2005.

They found that the narcolepsy incidence for vaccinated individuals within this age group was 9.0 per 100,000 people, as compared to just 0.7 per 100,000 for unvaccinated individuals – almost 13 times lower.

Together, these results provide compelling evidence that the Pandemrix vaccine, used in 2009 and 2010 in association with the H1N1 flu pandemic, contributed to narcolepsy in patients between the age of 4 and 19 in Finland, the authors conclude.

More information: Nohynek H, Jokinen J, Partinen M, Vaarala O, Kirjavainen T, et al. (2012) AS03 Adjuvanted AH1N1 Vaccine Associated with an Abrupt Increase in the Incidence of Childhood Narcolepsy in Finland. PLoS ONE 7(3): e33536. doi:10.1371/journal.pone.0033536

Partinen M, Saarenpa-Heikkila O, Ilveskoski I, Hublin C, Linna M, et al. (2012) Increased Incidence and Clinical Picture of Childhood Narcolepsy following the 2009 H1N1 Pandemic Vaccination Campaign in Finland. PLoS ONE 7(3): e33723. doi:10.1371/journal.pone.0033723

Provided by Public Library of Science