How Your Flu Vaccine May Protect Those Around You

Influenza vaccination in healthy adults linked to less flu-related illness in seniors

(RxWiki News) Adults who get their yearly flu vaccines may wind up protecting more than just themselves.

A new study from the Cleveland Clinic found that higher rates of flu vaccination among adults younger than 65 were linked to lower rates of flu-related illness among the elderly — a group at high risk of flu complications.

"In round numbers, we estimated that about 1 in 20 cases of influenza-related illness in the elderly could have been prevented if more non-elderly adults had received the flu vaccine," said lead study author Glen B. Taksler, PhD, a physician at the Cleveland Clinic, in a press release.

Jane Sadler, MD, a family medicine physician at Baylor Medical Center at Garland, TX, shared with dailyRx News some other benefits of flu vaccination.

"The flu shot saves lives and reduces hospitalizations," Dr. Sadler said. "The flu shot reduced children’s risk of ICU (intensive care unit) admissions by 74 percent during flu seasons 2010-2012. Another study demonstrated a decline in flu-related hospitalizations among adults of all ages during the 2011-2012 flu seasons (CDC)."

For this study, Dr. Taksler and team looked at more than 3 million US adults across eight flu seasons. Seniors were found to be up to 21 percent less likely to be diagnosed with a flu-related illness if they lived in areas where more adults under 65 were vaccinated.

Dr. Taksler and team also compared vaccination rates among adults ages 18 to 64 in various counties.

Counties with higher vaccination rates had lower overall instances of flu in older adults.

The risk of seniors getting the flu was more than 10 percent lower in counties with a 31 percent or higher vaccination rate. This risk reduction was doubled when the seniors themselves were vaccinated.

According to these researchers, vaccines can create "herd immunity," which means that unvaccinated people are protected from illness because they are surrounded by healthy, vaccinated people.

Herd immunity is particularly important for older adults because they tend to have more serious flu complications due to weakened immune systems. Flu vaccines are also not as effective for the elderly.

According to the Centers for Disease Control and Prevention (CDC), between 80 and 90 percent of all flu-related deaths and more than 50 percent of all flu-related hospitalizations occur in people older than 65.

Everyone older than 6 months should get a flu vaccine every season, according to the CDC.

"Flu season is October to May," Dr. Sadler said. "The flu vaccine may take up to two weeks for the body to develop antibodies to the influenza. September is NOT too early and the CDC recommends that flu vaccines continue to be offered throughout the flu season even into March."

This study was published Sept. 10 in the journal Clinical Infectious Diseases.

The National Institutes of Health funded this research. Study author Dr. David M. Cutler disclosed ties to Aetna Insurance and Novartis.

Review Date: 
September 9, 2015