Physicians have a new option this year for vaccinating patients aged 65 and older against seasonal influenza, but vaccine experts can't say for sure whether it will keep more people from getting the flu, according to findings in the Morbidity and Mortality Weekly Report.
On Dec. 23, 2009, the Food and Drug Administration licensed Sanofi-Pasteur's Fluzone High-Dose vaccine, an injectable inactivated trivalent influenza vaccine that provides four times the amount of antigen contained in standard flu vaccines. The aim is to increase the immune response among older adults, who are at greater risk for hospitalization and death from seasonal influenza. The new vaccine will be available for the first time in the 2010–2011 flu season.
Immunogenicity data from pre-licensure clinical trials showed that people aged 65 and older who received the high-dose vaccine had significantly higher hemagglutination inhibition titers against all three influenza virus strains, compared to the standard-dose Fluzone vaccine. While the higher immune response to vaccination generally correlates with protection against influenza, it is still unclear whether it will translate into fewer vaccine recipients getting the flu this year, according to the report (MMWR. 2010;59:485-6).
About 36% of 2,572 people who received Fluzone High-Dose reported injection-site pain in the week after receiving the vaccine, compared with 24% of 1,275 who received standard-dose Fluzone. However, the reactions were generally mild and didn't last long.