Fall is the time for colorful foliage, cooler temperatures—and the beginning of cold and flu season. No mere nuisance, flu costs the U.S. more than $10 billion and takes about 3,600 lives each year. Vaccination is a powerful weapon against the seasonal illness, which poses particular health risks to the very young and the elderly.
But flu shots also have significant benefits for the heart. A 2013 study in the Journal of the American Medical Association found that flu vaccination provided protection against major heart events over the following year. Pooling data from six clinical trials involving more than 6700 people, about a third with heart disease, researchers showed that, overall, participants who received the flu shot had a 36 percent lower risk for having a heart attack, stroke or other cardiac event. Protection was even greater among those who had recently suffered a heart attack. A large NIH-supported clinical trial designed to study whether a high-dose vaccine can offer more protection to people with heart disease is about to get underway.
Why the protective effect? Infection with the flu virus prompts the body to mount a powerful immune response. The resulting inflammation can lead to plaque rupture and cause blockages related to heart attack and stroke. In addition the flu virus can lower blood oxygen in the lungs, making the heart work harder, and damage heart muscle cells, leading or contributing to heart failure. By avoiding the flu, this cascade of dangerous consequences can also be sidestepped.
The CDC recommends that everyone 6 months and older get a flu vaccine every year by the end of October, if possible. (It’s still helpful to get one later.) Unfortunately vaccination rates among adults age 50 to 64 dropped to less than 44 percent last year. Only 63 percent of adults ages 65 and older got the vaccine in the 2015-16 flu season.
A higher-dose vaccine is now available for people who are 65 and older. The vaccine contains four times the amount of antigen—the part of the vaccine that primes the body’s immune system—as the regular flu shot and seems to trigger a stronger immune response. A New England Journal of Medicine study found that the high-dose vaccine was 24 percent more effective in keeping flu at bay than a regular dose shot among people in that age group. Time will tell if that also translates into greater cardio-protection.
Although flu shots are far from perfect, they lower an individual’s risk of flu by about 50 to 60 percent. Considering that benefit, the risks illness poses to others, the disruption flu causes at home and work, and the dividends for your cardiovascular system, a flu shot should be a no-brainer for everyone.