Flu Vaccine May Lower Heart Attack Risk, Researchers Find

Flu vaccination may not only stave off the seasonal virus, it may prevent heart attacks too, researchers in Australia found.

Immunization against the respiratory illness lowered the probability of heart attack by 45 percent, according to a study of more than 500 hospital patients by researchers at the University of New South Wales in Sydney.

The finding, published today in the journal Heart, suggests flu vaccination programs targeting the elderly should be extended to include younger adults, especially those with coronary artery disease. Among seniors, the shot reduces severe illnesses and complications from flu by as much as 60 percent and deaths by 80 percent, according to the World Health Organization in Geneva.

“Flu vaccine could be having more of a public health impact than it already is,” said Raina MacIntyre, head of the school of public health and community medicine at UNSW and the study’s first author.

Previous research has shown that acute infections, such as influenza, cause the body to increase production of disease-fighting inflammatory proteins in the blood that can clog up vessels narrowed by heart disease, MacIntyre said.

“We know that every flu season, heart attacks increase,” she said. “To me, it’s fairly convincing evidence that flu vaccine can protect against heart attack in people who already have diseased arteries.”

Her study, which received funding from U.K. drugmaker GlaxoSmithKline Plc, found that almost 1 in 10 hospitalized patients had laboratory-confirmed flu, even though it wasn’t suspected or diagnosed at the time of their admission.

The research compared 275 hospitalized heart attack patients with 284 people who were treated in a hospital outpatient department from 2008 to 2010. It also found respiratory-tract infections doubled the risk of a heart attack, suggesting flu-fighting vaccines could also help prevent the leading cause of death and disability worldwide.

“There is a whole lot of people who are at risk of heart attack in the 50-to-65-year age group who are under-vaccinated,” MacIntyre said.

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