High-dose flu vaccines given to older adults lower pneumonia- and influenza-related (P&I) hospitalization, but there isn’t a difference in death rates between people who received the high-dose and standard-dose flu shots, a new study finds.
The report was published in the Journal of Infection.
The high-dose flu shot has four times as much hemagglutinin as standard-dose influenza shots and is recommended for adults aged 65 or more years. Older adults are at the highest risk for flu-related complications. The shot triggers a higher antibody response and has lowered the incidence of the flu in multiple studies, according to the authors of the current study.
The authors of the current study looked at existing studies on the shots during at least one flu season since 2009. Data came from 105,685 older adults. The mean age of participants across studies ranged from 66 to 85 years.
The high-dose flu shot had a P&I hospitalization rate of 0.8% compared with 1.1% in the standard flu shot. The high-dose shot showed an average vaccine efficacy of 23.5%.
When the team looked at how the shots performed with regard to all-cause hospitalization, they saw that 14.1% of high-dose flu shot recipients were hospitalized during the follow-up period, compared with 15.2% of those who had received the standard dose. The high-dose vaccine efficacy was 7.3%.
Investigators cited the DANFLU-2 trial, which is expected to conclude in 2025. That trial will look at P&I hospitalization in individuals aged 65 and older. The authors said that the results of that trial would provide further valuable evidence on the use of high-dose flu shots in older adults.The news comes as another recent report found the protective effect of annual flu vaccines does not erode when older adults receive flu shots every year. There wasn’t a significantly increased risk of influenza in consecutively vaccinated participants compared with those receiving the vaccine only in the current season, the data showed.
