Febrile adverse events associated with CSL Biotherapies' 2010 Seasonal Influenza Vaccine

CSL’s 2010 Southern Hemisphere seasonal influenza vaccine, Fluvax^®, was associated with increased reports of febrile events in children compared to previous seasons. The febrile events occurred predominantly in children under the age of five years, shortly after vaccination.

To determine the root cause of these events, CSL has conducted clinical, manufacturing and scientific investigations involving Australia’s Therapeutic Goods Administration (TGA), the US Food and Drug Administration (FDA) and other international experts. CSL expects to conclude these investigations in the early part of 2012 and following appropriate consultation with regulators, will make the results publicly available. Read about our status of investigations.

To mitigate the risk of further febrile events in children, Fluvax^® vaccine is currently licensed for use in people aged 5 years and above and the prescribing information for Fluvax^® vaccine contains a boxed warning to this effect.

In 2010, there were also reports of fever and associated symptoms in children aged between five and less than nine years following use of Fluvax^® vaccine. As a result, the product information for Fluvax^® vaccine contains a precaution about its use in this age group, and the Australian Technical Advisory Group on Immunisation (ATAGI) recommends that Fluvax^® vaccine only be used in children aged five years to less than ten years when no timely alternative vaccine is available and parents are informed of the increased potential increased risk of fever. CSL fully supports the ATAGI recommendations.

Ongoing safety monitoring of CSL’s seasonal influenza vaccine in both Southern and Northern Hemisphere countries has not identified any safety concerns with its use in older children and adults.

Until a root cause for the unexpected increase in febrile reactions has been resolved, CSL will continue to work with regulators and vaccine policy makers in all relevant countries to ensure age-appropriate restrictions and risk mitigation strategies are in place for the use of its seasonal influenza vaccine.

Parents wishing to have their children vaccinated against influenza or who have any concerns about influenza vaccination should seek advice from their doctor.