Flu Vaccine May Lower Risk of Heart Attack

Flu vaccines may protect against more than just fever and chills: according to a new study, the shot may also protect against heart attacks and other kinds of adverse cardiovascular events.

"Among nontraditional cardiovascular risk factors, there remains interest in a potential association between respiratory tract infections, of which influenza and influenza-like illnesses are common causes, and subsequent cardiovascular events," the authors of the study wrote.

Published in the Journal of the American Medical Association, the report consisted of a meta-analysis of previous studies in which more than 6,000 participants were randomly assigned a flu vaccine, a placebo or neither. Of those included in the studies, roughly one-third had previously suffered from heart problems. The average follow-up time was 8 months and the average age was 67.

From the group that received flu shots, roughly 3 percent went on to experience a major adverse cardiovascular event, compared to nearly 5 percent from those of the other two groups.

The difference between the groups was even greater in the case of individuals with a history of acute coronary syndrome (ACS). Among this demographic, roughly 10 percent of those who received flu shots later experienced a major heart problem, versus 23 percent of those who received either a placebo or no treatment.

Based on their findings, the researchers concluded: "Future research with an adequately powered multicenter trial to confirm the efficacy of this low-cost, annual, safe, easily administered, and well-tolerated therapy to reduce cardiovascular risk beyond current therapies is warranted."

While the study was not able to prove that flu shots were the reason behind the decrease in significant heart problems, Dr. Kathleen Neuzil, a researcher from the University of Washington School of Medicine, points out that getting vaccinated is a good idea anyways.

"Regardless of whether influenza vaccine reduces cardiovascular disease, the known morbidity of influenza in older adults with and without high-risk conditions and the known efficacy of the vaccine warrant its use," she said in an editorial that accompanied the study. "All health care practitioners can recommend influenza vaccination to their patients."