HELSINKI/LONDON May 23 GlaxoSmithKline Plc's
H1N1 pandemic flu shot may put adults at higher risk of
developing narcolepsy, not only children as previous studies
found, Finland's National Institute for Health and Welfare said
Growing evidence of a link between GSK's Pandemrix vaccine
and an increase in narcolepsy, a rare sleep disorder, among
children who received it in Europe has delayed approval of a
similar vaccine in the United States.
Data published this year in the British Medical Journal
found that children in England who had been vaccinated with
Pandemrix during the 2009-10 H1N1 swine flu pandemic had a
14-fold higher risk of developing narcolepsy, equating to about
one in 50,000.
Finland's National Institute said an analysis of hospital
and primary care data in Finland found that people aged between
20 and 64 who had been vaccinated with Pandemrix were 3 to 5
times more likely to develop narcolepsy than unvaccinated
Narcolepsy is a lifelong, incurable and potentially
debilitating sleep disorder that can cause hallucinations,
bouts of daytime sleepiness and cataplexies - where strong
emotions trigger a sudden loss of all muscle strength.
Previous studies in Finland, Sweden and Ireland have also
found a link between Pandemrix and narcolepsy, and GSK says more
than 800 cases linked to the shot have been reported in Europe.
The British drugmaker says some 30 million doses of the
vaccine were administered across Europe during the 2009-10 H1N1
pandemic. The pandemic was declared over in August 2010.
The company acknowledges an association but says there is as
yet insufficient evidence to show that Pandemrix is the cause.