The two currently available flu vaccines specifically for older adults showed similar safety profiles, based on data from 757 individuals.

An older man receives a flu shot. copyright Wavebreakmedia/Thinkstock

The Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices (ACIP) recommends that age-appropriate vaccines be used when possible, said Kenneth E. Schmader, MD, professor of medicine at Duke University, Durham, N.C. However, no study to date had directly compared the safety of the trivalent high dose (HD-IIV3) and adjuvanted (aIIV3) vaccines or their impact on health-related quality of life. Dr. Schmader presented findings from a randomized trial at the February ACIP meeting.

To compare the safety of the vaccines, the researchers recruited community-dwelling volunteers aged 65 years and older who were cognitively intact, not immunosuppressed, and had no contraindications for influenza vaccination. A total of 378 individuals were randomized to aIIV3 and 379 to HD-IIV3. The average age was 72 years; 80 individuals in the aIIV3 group and 83 in the HDIIV3 group were 80 years and older. The primary outcome was moderate or severe injection site pain.

Overall, the proportion of participants with moderate or severe injection site pain was not significantly different after aIIV3 vs. HD-IIV3 (3.2% vs. 5.8%).

Nine participants in the aIIV3 group and three participants in the HD-IIV3 group experienced at least one serious adverse event, but no serious adverse events were deemed vaccine related, and the occurrence of serious adverse events was not significantly different between groups.

In addition, measures of short-term, postvaccination health-related quality of life were not significantly different between the groups. Changes in scores from day 1 prevaccination to day 3 postvaccination on the EuroQOL-5 dimensions-5 levels (EQ-5D-5L) were –0.05 for both groups.

The findings were limited in part by the lack of inclusion of older adults in nursing homes or similar settings, Dr. Schmader noted. However, the results suggest that “from the standpoint of safety, either vaccine is an acceptable option for the prevention of influenza in older adults.”

Studies comparing the immunogenicity of the vaccines are ongoing, and the data should be available within the next few months, he noted.

Dr. Schmader had no financial conflicts to disclose.