LYON, France, Aug. 13, 2014 /PRNewswire/ -- Sanofi Pasteur, the vaccines division of Sanofi (EURONEXT: SAN and NYSE: SNY), today announced that The New England Journal of Medicine published positive results from a large-scale, multi-center efficacy trial, which found that Fluzone ® High-Dose (Influenza Vaccine) was more efficacious in preventing influenza ("the flu") in adults 65 years of age and older compared to standard-dose Fluzone vaccine.
Fluzone High-Dose vaccine was found to be 24.2 percent (95% CI, 9.7 to 36.5) more effective in preventing influenza relative to standard-dose Fluzone vaccine for the primary endpoint, indicating that about one in four breakthrough cases of influenza could be prevented if Fluzone High-Dose vaccine were used instead of the standard-dose Fluzone vaccine in this population. Additionally, relative efficacy was 35.4 percent (95% CI, 12.5 to 52.5) in an analysis restricted to influenza cases caused by vaccine-similar strains.
Fluzone High-Dose vaccine is an inactivated influenza vaccine that contains four times the amount of antigen than is contained in standard-dose Fluzone vaccine and induces a higher antibody response.
" We are thrilled that the results of this trial have shown that Fluzone High-Dose vaccine is significantly more effective than standard-dose Fluzone vaccine in providing protection against influenza in the 65 and over population," said David P. Greenberg, M.D., Vice President, Scientific & Medical Affairs, and Chief Medical Officer, Sanofi Pasteur US. "Fluzone High-Dose vaccine is the only influenza vaccine in the US that is designed specifically to address the age-related decline of the immune system in older adults."Investigators compared the vaccine's efficacy in a large-scale, randomized, double-blind, trial that spanned two influenza seasons. The trial enrolled nearly 32,000 participants; 14,500 and 17,489 adults 65 years of age and older during the 2011-2012 and 2012-2013 influenza seasons, respectively, from 126 research centers in the United States and Canada. The primary endpoint of the study was the occurrence of laboratory-confirmed influenza at least 14 days post-vaccination caused by any influenza viral type or subtype. Investigators determined that participants in the Fluzone High-Dose vaccine group were less likely to get the flu than those in the standard-dose Fluzone vaccine group. Specifically, 228 people in the Fluzone High-Dose vaccine group (1.43 percent) and 301 people in the standard-dose Fluzone vaccine group (1.88 percent) had laboratory-confirmed influenza, demonstrating that Fluzone High-Dose vaccine was 24.2 percent (95% CI, 9.7 to 36.5) more effective in preventing influenza than standard-dose Fluzone vaccine. Additionally, researchers determined that most rates for pneumonia, cardio-respiratory conditions, hospitalizations, non-routine medical office visits and medication use were lower for the Fluzone High-Dose vaccine group compared to the standard-dose Fluzone vaccine group. "Eighty-six percent of older adults have one or more chronic conditions, such as, cardiovascular disease and respiratory illnesses that can be exacerbated by influenza," [i] said Keipp Talbot, MD, MPH, Assistant Professor of Infectious Diseases, Vanderbilt University Medical Center, Nashville, Tenn. and coordinating investigator of the trial. "Considering the burden of influenza in older adults, it is encouraging to see that this trial demonstrated the ability of Fluzone High-Dose vaccine to provide better protection in this high-risk population." The full results from this trial formed the basis for a regulatory submission to the U.S. Food and Drug Administration (FDA) late last year to seek a modification to the Prescribing Information for Fluzone High-Dose vaccine reflecting the improved efficacy compared to standard-dose Fluzone vaccine in adults 65 years of age and older. Sanofi Pasteur anticipates a decision later this year.