The vaccine used against swine flu has been linked to a disorder called narcolepsy among those aged four to 19. Narcolepsy involves people falling asleep without warning or sleeping excessively in the daytime. A preliminary study also “observed [an] increase in incidence of narcolepsy” among those given the vaccine.
The study, published by Finland’s National Institute for Health and Welfare, said that “the most likely explanation for the findings is that the increase in narcolepsy is by joint effect of the vaccine and some other factor.” The researchers based their findings on discharge data from patients who were hospitalized with narcolepsy during 2009 and 2010. They used primary care records to gather data on pandemic vaccination. Narcolepsy was reported in 60 Finnish children and adolescents in 2009 and 2010. A panel of neurologists and sleep researchers reviewed their records. Of those with narcolepsy, 52 (nearly 90%) had received the Pandemrix vaccine. Vaccine coverage for the entire group was 70%. “The observed association is so evident that it is unlikely that other so-called confounding factors could fully explain the phenomenon,” the group said in a press release.
However, the Medicines and Healthcare products Regulatory Agency (MHRA), which regulates medicines in Britain, emphasized there was no confirmed link between vaccination and narcolepsy. A spokesman from MHRA said, “This signal has not been seen outside of Scandinavia and the exact reason why more reports of narcolepsy have been identified in Finland needs further scrutiny…As noted in the Finnish report, there has also been an increase in the number of narcolepsy reports in unvaccinated people in Sweden and Iceland, so a relationship with the vaccine is far from clear cut.” He added that the Pandemrix vaccine remained available and should continue to be used as recommended.
Last August, the European Medicines Agency announced it was investigating a possible link between the swine flu vaccine and narcolepsy. GlaxoSmithKline, which produces Pandemrix, said it was aware of the Finnish report. A GSK spokesman said, “This investigation is independent of a broader ongoing European Medicines Agency investigation initiated in 2010…GlaxoSmithKline is reviewing the report and believes it would be premature to draw any conclusions on a potential association between Pandemrix and narcolepsy until this European investigation has been completed.” GSK revealed that till date more than 31 million doses of Pandemrix had been administered in 47 countries with 162 cases of narcolepsy reported in people who were vaccinated. Some 70 per cent of these cases were in Finland and Sweden, it said.
Department of Health spokeswoman said, “The European Medicines Agency has strict processes in place for licensing vaccines and for monitoring their safety. These are important to ensure vaccine safety and to maintain public confidence in vaccination…Flu vaccines have an excellent safety record. More than six million doses of the H1N1 vaccine has been given in the UK. There were no unexpected safety issues and the safety profile was reassuring.”
The World Health Organization (WHO) in its statement today said that it was aware of the preliminary report from Finnish health officials and agrees that further study is needed. It said its Global Advisory Committee on Vaccine Safety is considering all available data on the increased narcolepsy reports and will issue a statement within the coming days. “Recommendations for the use of seasonal 2010/2011 influenza vaccines in children and adolescents remain unchanged,” the WHO added.
Promising influenza drug candidate shows activity against resistant variants