Influenza Vaccine Reduces Risk of Heart Disease and Stroke in Elderly, Study Says

People older than age 65 who receive influenza vaccinations are less likely to be hospitalized for heart disease or a stroke, according to a study in today's New England Journal of Medicine, the AP/New York Times reports (AP/New York Times, 4/3). The study, conducted by researchers at the Veterans Affairs Medical Center in Minneapolis and the University of Minnesota, examined the medical records of more than 286,000 seniors enrolled in three managed care plans during the 1998-1999 and 1999-2000 flu seasons. The researchers compared hospital stays for those who received flu shots and those who were not vaccinated. The study found that the risk of seniors who received flu shots of being hospitalized for heart disease fell by 19%, while their risk of being hospitalized for stroke fell by as much as 23% (Tomsho, Wall Street Journal, 4/3). Researchers also found that immunization reduced hospital stays by 32% for the flu and pneumonia, the Reuters/Los Angeles Times reports (Reuters/Los Angeles Times, 4/3).

Dr. William Schaffner, head of preventative medicine at Vanderbilt University School of Medicine, said the results need to be "investigated further" but that the study "offers even more reassurance and affirmation as to the importance of getting your flu shot annually," the AP/Times reports (AP/New York Times, 4/3). While the relationship between flu shots and cardiovascular disease is not known, scientists believe that the flu virus can alter clotting proteins and impair the function of blood vessels, the Journal reports. "[W]e don't have to wait until we understand every last detailed mechanism," Dr. Kristin Nichol, chief of medicine at the Minneapolis VA center and the study's leader researcher, said, adding, "We know that immunization and the prevention of influenza has such huge benefits for people that we should be using the vaccine more than we are now" (Wall Street Journal, 4/3). The study abstract is available online.