In 2013, scientists and governments estimated that there were close to 800 narcolepsy cases tied to GlaxoSmithKline's ($GSK) now-withdrawn swine flu vaccine, Pandemrix. And now, a team of scientists at Stanford University believes they have discovered the link.
|Stanford's Lawrence Steinman|
In a study published in Science Translational Medicine, Lawrence Steinman and colleagues said a protein contained in the H1N1 virus was found in high amounts in GSK's vaccine and much lower levels in Novartis' jab, which was also used in the 2009/2010 swine flu pandemic. Though both vaccines were widely deployed, only GSK's was linked to narcolepsy.
The team found that the protein partly mimics a portion of a hypocretin receptor in the brain, causing narcolepsy through a so-called "hit-and-run" mechanism in which high levels of the protein caused antibodies--to both the virus and the hypocretin receptor--to be produced at a high level.
In its response, GSK said it would review the findings carefully. More than 30 million people in 47 countries received Pandemrix during the swine flu pandemic.
"We are actively conducting research into the observed association between Pandemrix and narcolepsy and the interaction this vaccine might have had with other risk factors in those affected," a spokesperson told Reuters.
Last month in the U.K., a 12-year-old boy was awarded £120,000 in damages for his narcolepsy following a three-year legal battle, a ruling expected to lead as many as 100 other families to seek compensation.
Wednesday's findings aren't the only research purporting to explain the link between Pandemrix and narcolepsy. In December, a team in Finland compared Pandemrix with Arepanrix--a shot used in Canada with the same adjuvant--and found that GSK's shot had more of one structurally altered viral nucleoprotein. Lead researcher Outi Vaarala said the variation could be traced to the way the vaccines were prepared.
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