High-dose influenza vaccines, those with higher antigen content compared to standard-dose flu vaccines, is more effective at preventing illness among people older than 65 years, according to a study published in Clinical Infectious Diseases.
Researchers conducted the study using data from eight hospitals enrolled in the United States Hospitalized Adult Influenza Vaccine Effectiveness Network during the 2015-16 and 2016-17 flu seasons.
They analyzed data for 1,487 patients, of which 1,107 were vaccinated, with 622 receiving a high-dose flu vaccine, and 485 receiving a standard-dose vaccine.
Nineteen percent of the patients overall tested positive for the flu, of which 16 percent received the high-dose vaccine and 18 percent received the standard-dose vaccine. Twenty-four percent were unvaccinated.
Researchers found that the effectiveness of the standard-dose vaccine among the seniors was 6 percent, while the effectiveness of the high-dose vaccine was 32 percent.