Sep 9, 2010 (CIDRAP News) – Preliminary results from an investigation by Swedish regulators into reports of narcolepsy in people who received a 2009 H1N1 vaccine found no link between the immunization and the condition.
In a report yesterday from the country's Medical Products Agency, investigators said they found that narcolepsy developed both in people who had and who had not received the vaccine, Finland-based YLE News reported yesterday.
The agency's report said six narcolepsy cases in Stockholm were in children, two of whom had not received the Pandemrix vaccine, according to the YLE report. Of 10 narcolepsy cases reported in adults, half had received the vaccine. Pandemrix is made by GlaxoSmithKline and contains an adjuvant.
Dr Ville Valtonen, an infectious disease specialist in Finland, told YLE that respiratory infections with high fever, such as 2009 H1N1 infections, can trigger narcolepsy.
Despite the findings of Swedish regulators, Finnish officials are maintaining their recommendation that doctors suspend the use of Pandemrix, YLE reported. The country's health officials have received 26 reports of suspected narcolepsy, 21 of them in children younger than 15.
On Aug 27 Europe's drug regulatory agency launched a review of Pandemrix in the wake of reports of narcolepsy through Swedish and Finnish reporting systems. The agency said it would review all the data and determine the background rate of narcolepsy. It said it would decide at its meeting this month whether to take any action on the vaccine while completing its investigation.
A few days later, on Sep 1, the US Centers for Disease Control and Prevention (CDC) released a statement on the vaccine-narcolepsy concerns, noting that Pandemrix, which has been administered to 30.8 million Europeans, has not been licensed in the United States.
The CDC said it reviewed information from the US Vaccine Adverse Event Reporting System (VAERS) and found no signals or concerns linking the US pandemic and seasonal flu vaccines to narcolepsy. The agency said it has enhanced surveillance for narcolepsy cases that occur after administration of the 2010-11 seasonal flu vaccine, which contains the 2009 H1N1 virus as one of three subtypes.
Sep 8 YLE News report
Sep 1 CDC statement