Image of Jerry Avorn, M.D.; Image credit: Harvard University
Jerry Avorn, M.D.; Image credit: Harvard University

Older adults who receive an influenza and shingles shot on the same day are less likely to get a flu shot the following year, a new study finds. Enhanced patient education about side effects may prevent later vaccine hesitancy, the authors contend.

Physician researchers compared the next-year’s flu vaccination rates among people who got their flu and shingles shots concurrently and those whose shots were at least 29 days apart. The data came from more than 89,000 insurance recipients aged 50 years and older.

In the following year, flu shot uptake was lower among the more than 27,000 individuals who had received their shots on the same day a year earlier when compared with the more than 62,000 individuals who received the vaccines on separate days, the researchers found. The results were similar across various subgroups studied.

Side effects are nothing to sneeze at

The takeaway? Shingles vaccine side effects are nothing to sneeze at, the researchers surmised. 

“One possible explanation is that some patients could have misattributed systemic side effects caused by the zoster vaccine to the influenza vaccine,” wrote study lead Jerry Avorn, M.D., of Brigham and Women’s Hospital Boston and Harvard Medical School.

Considering the poor uptake of influenza vaccination in general — fewer than half of U.S. adults receive the flu vaccine each year — clinicians may want to consider administering these two vaccines separately, he and his fellow authors suggested. Another option would be to provide additional patient education about expected vaccine side effects, they said. 

Most people have a sore arm with mild or moderate pain after getting Shingrix, the current shingles vaccine recommended by the Centers for Disease Control and Prevention. Some also experience redness and swelling at the injection site. Others feel tired, have muscle pain, a headache, shivering, fever, stomach pain, or nausea, the CDC reports.

The trick is to weigh the implications of the new study findings against the known challenges of encouraging patients to return for vaccines when they must make two separate visits, the researchers cautioned. 

“Proper counseling for those who receive both the flu and zoster vaccines could be critical for mitigating vaccine hesitancy in subsequent years,” they concluded.

Data for the study was drawn for the 2019-2020 season from a national commercial insurance claims database and Medicare Advantage plans.

Full findings were published in JAMA Network Open.