Do Elderly Patients Even Benefit from the Flu Vaccine?

The debate over whether influenza vaccines are valuable in elderly patients may be put to end as a study from Brown University has verified that the strategy has made a positive impact.

The Centers for Disease Control and Prevention (CDC) identifies people age 50 and older as a priority to receive flu vaccines and a recent report found that the group is not meeting vaccination rates. Some healthcare workers are skeptical about the benefit of flu vaccines in the elderly despite the fact that it’s standard practice in nursing homes.

To make a case about the positive influence of flu vaccines, and recognize any trends over the years, the team examined records from more than one million patients in long-term nursing home stays between 2000 and 2009. Three strains were included in the analysis: A/H1N1, A/H3N2, and B.The researchers noted that the virus mutates year-to-year, causing a new vaccine to be developed annually, which results in some vaccines matching and being more effective than others.

“What we’ve used is the randomness of the match. Ours is the first study to, we think come up with an unbiased approach,” corresponding author Vincent Mor, the Florence Pirce Grant Professor in the Brown University School of Public Health, said in a news release.

The report appearing in the Journal of the American Geriatrics Society revealed data on pneumonia and influenza (P&I) hospitalizations and mortalities from week-to-week. The average amount of hospitalizations was 2.05 to 2.43 per 1,000 patients and mortalities ranged from 3.74 to 4.13.This added up to about 77,000 hospitalizations and 130,000 deaths during the 32 non-summer weeks. Vaccine match rates were better in the A/H1N1 strain compared to the other two during all of the seasons.

“The association between vaccine match and reduction in overall mortality and P&I hospitalizations was strongest for A/H3N2, the influenza strain typically responsible for the most-severe influenza cases,” the authors wrote.

Further analysis by the team determined that “the model estimated that a 50-percentage-point increase in the A/H3N2 match rate (from <25% to >75%) reduced long-stay [nursing home] resident deaths by 2.0% and P&I hospitalizations by 4.2%.”

To put those numbers into perspective, the 50-percentage-point increase match would prevent 3,200 hospitalizations and 2,560 deaths out of the one million patients included in the study alone. Mor explained that more older people in nursing homes get vaccinated than those who are not — which presents another concern.

“This study evidences protection for an elderly population for whom vaccine efficacy has been questioned,” concluded co-author Stefan Gravenstein, adjunct professor of medicine and health services, policy and practice. “Annual vaccination is the only way to maximize the benefit of vaccine, no matter what the age.”