UK study confirms GlaxoSmithKline flu shot link to rare sleep disorder
The vaccine, more than 30 million doses of which were given during the H1N1 flu pandemic in 2009-2010, contains a booster, or adjuvant, and may have triggered an adverse immune reaction in some children at higher genetic risk of narcolepsy, scientists said in new research published on Wednesday.
Researchers at Britain's Health Protection Agency (HPA) who published the study in the British Medical Journal said the at least 14-fold increased risk they found had "implications for the future licensing and use of adjuvanted pandemic vaccines".
Narcolepsy is a life-long disorder and thought to be an autoimmune disease in which patient's immune system attacks the body's own cells. Its symptoms include frequent bouts of daytime sleepiness and in its severe forms it also causes night terrors, hallucinations and cataplexies - when strong emotions trigger a sudden loss of muscle strength.
Studies in Finland, Sweden and Ireland have also found a Pandemrix link to narcolepsy, and GSK says more than 800 cases linked to the shot have been reported in Europe.
A spokesman for the British drugmaker told Reuters on Wednesday: "We really want to get to the bottom of this and understand more about the potential role of Pandemrix in the development of narcolepsy."
He added, however, that GSK believes "the available data are insufficient to assess the likelihood of a causal association between