CSL Biotherapies indentifies likely reason for Fluvax problems

Australia’s largest biotech firm CSL Biotherapies, a division of CSL Limited (ASX: CSL) today presented preliminary conclusions from its investigations into the cause of the unexpected adverse events associated with Fluvax influenza vaccine in 2010, suggesting that a manufacturing method used in CSL's 2010 flu vaccine triggered an excessive immune response in some young children who suffered fevers and convulsions, a preliminary investigation has found.

During the influenza season of 2010, Fluvax was associated with increased reports of fever-related (febrile) convulsions in children compared to previous seasons. The convulsions occurred predominantly in children under the age of five years, shortly after vaccination. The rate of febrile convulsion following administration of Fluvax in 2010 was estimated to be five to seven per 1,000 doses. Fluvax has not been licensed for use in children aged under five years since these events, note the company, which is Australia’s only on-shore manufacturer of influenza vaccine.

Two-year investigation monitored by TGA and FDA