Close up image of a caretaker helping older woman walk

A higher dose of a flu vaccine has been shown to significantly improve the immune system’s response to the actual virus, especially among the elderly, researchers told the American Geriatrics Society at the Annual Scientific Meeting earlier this month.

Researchers, led by Ann R. Falsey, MD, Associate Professor of Medicine at the University of Rochester School of Medicine and Dentistry in New York, tested a high-dose vaccine on more than 2,500 seniors with an average age of 73. They found that the high dose drastically out-performed a normal dose among seniors when it came to influenza A strains. There was no significant statistical difference between low-dose vaccines and high-dose vaccines in preventing influenza B strains.

Researchers also noticed a higher instance of localized irritation around the injection site with the higher dose vaccines. A total of 54% of high-dose recipients experienced irritation, compared with 44% of normal-dose recipients. Irritation was described as temporary and mild, however, and no other complications arose.