Fluzone High-Dose More Effective Than Standard Dose in Older Adults

Results from a large clinical trial of Sanofi Pasteur’s Fluzone High-Dose showed that the influenza vaccine was 24.2 percent more effective against lab-confirmed flu than the traditional vaccine dose in adults 65 and older. The Phase III trial was conducted over the past two flu seasons (2011-2012, which was considered one of the mildest in the past several years, and 2012-2013, which was considered moderately severe) at 126 centers across the U.S. and Canada, enrolling approximately 32,000 seniors. Half of the patients received the high-dose vaccine and the other half were administered the standard-dose vaccine. There was no placebo group. The researchers routinely called participants to ask about flu-like symptoms, and the study subjects were also asked to report any symptoms. When symptoms were reported, medical teams obtained nasopharyngeal swabs. Safety findings were similar to earlier findings, which showed a slightly higher risk of local reactions but not of serious adverse events. Fluzone High-Dose was approved in 2009 for  adults 65 and older and contains four times as much antigen as standard-dose flu vaccines.