When the influenza vaccine is well matched to the prevailing strains of flu in a given season, patients in nursing homes are significantly less likely to be hospitalized or to die of pneumonia and other influenza related causes. The finding comes from a study of more than 1 million Medicare fee-for-service long-stay nursing home residents. When the vaccine's match with A/H3N2 - the influenza strain typically responsible for severe symptoms - was excellent (75%) during an A/H3N2 predominant season, there was an estimated 2.0% reduction in deaths and a 4.2% reduction in pneumonia and influenza hospitalizations compared with a year with a poor match (25%).

"This translates into approximately 2,560 lives saved and more than 3,200 hospitalizations prevented annually for long-stay nursing home residents in the United States," said Dr. Vincent Mor, lead author of the Journal of the American Geriatrics Society study.

Study: Estimating the Effect of Influenza Vaccination on Nursing Home Residents' Morbidity and Mortality, Pop-Vicas, A., Rahman, M., Gozalo, P. L., Gravenstein, S. and Mor, V., Journal of the American Geriatrics Society, doi: 10.1111/jgs.13617, published online 17 August 2015.