High-dose influenza vaccine significantly reduced the risk of serious cardio-respiratory events possibly related to influenza in seniors ages 65 and over, when compared to the standard-dose vaccine, according to a Vanderbilt-led study published today by the journal Vaccine.
The large-scale, multi-center efficacy trial was led by Keipp Talbot, M.D., MPH, assistant professor of Medicine at Vanderbilt University Medical Center, who served as coordinating investigator for the more than 100 study sites.
Known as the Fluzone High-Dose vaccine, and made by Sanofi Pasteur, the inactivated influenza vaccine contains four times the amount of antigen that is contained in the standard-dose Fluzone vaccine.
Talbot and co-authors reported today that the high-dose influenza vaccine, compared to standard-dose influenza vaccine, was associated with an 18 percent reduction in serious cardio-respiratory events possibly related to influenza overall, and a 40 percent reduction in serious pneumonia.
"The high-dose influenza vaccine not only reduces influenza but also significantly reduces the potential for pneumonia during influenza season," Talbot said. "This is an important finding and supports the annual use of high-dose influenza vaccine in older adults."
In the study, nearly 32,000 adults ages 65 and over were randomly assigned to receive either Fluzone High-Dose vaccine or Fluzone vaccine, and followed for six-to-eight months post-vaccination for the occurrence of influenza and serious events.
Events were grouped into the following categories: pneumonia, asthma, chronic obstructive pulmonary disease (COPD) or bronchial events, influenza (laboratory-confirmed influenza diagnosed outside of normal study procedures), other respiratory events, coronary artery events, congestive heart failure, and cerebrovascular events.
"Influenza and pneumonia combined is the eighth leading cause of death in older adults in this country, so it is especially important that this analysis showed lower rates of serious cardio-respiratory events, most notably serious pneumonia, in the Fluzone High-Dose vaccine group compared to the Fluzone group," 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 United States that is designed specifically to address the age-related decline of the immune system in older adults," he said.
Prior research from Talbot and her co-authors, published in the New England Journal of Medicine in August 2014, demonstrated that the high-dose vaccine was 24 percent more effective in preventing clinically relevant laboratory-confirmed influenza.
Fluzone High-Dose vaccine is indicated for active immunization for the prevention of influenza disease caused by influenza A subtype viruses and type B virus contained in the vaccine.
The most common local and systemic adverse reactions to Fluzone High-Dose vaccine include pain, erythema, and swelling at the injection site; myalgia, malaise, headache and fever.