With flu vaccines arriving in pharmacies and National Immunization Awareness Month well under way, the benefits of vaccines have been well documented in recent weeks. And a new study shows flu vaccines may provide even more benefits than originally thought.
The observational study looked at 559 hospital patients at the University of New South Wales and found immunization against flu cut the likelihood of heart attack by 45%. Data from the Australian study adds to epidemiological evidence linking influenza infection to cardiovascular hospitalizations, acute myocardial infarction and death. Collectively, the findings suggest healthcare systems may underestimate the health and economic benefits of vaccinating people aged 50 to 65 years old against influenza.
"Flu vaccine could be having more of a public health impact than it already is. We know that every flu season, heart attacks increase. To me, it's fairly convincing evidence that flu vaccine can protect against heart attack in people who already have diseased arteries," study co-author Raina MacIntyre told Bloomberg. Writing in the journal Heart, MacIntyre and her collaborators speculate that influenza and other acute infections increase the risk of heart disease because they cause the body to boost production of inflammatory proteins. These proteins then block blood vessels, leading to heart disease.
GlaxoSmithKline ($GSK) supported the study with a grant and stands to benefit if the evidence in the Heart paper contributes to an expansion of vaccine recommendations. While the Centers for Disease Control and Prevention (CDC) recommends flu vaccines for everyone aged 6 months and older, other countries, such as Australia, focus immunizations on high-risk groups. A 2009 paper in Pharmacoeconomics had doubts about whether extending flu vaccinations in Australia to the 50-to-64-year-old age group would be cost effective. Evidence the flu vaccine cuts the risk of heart attacks could make the economics more favorable and open up a new market for GSK and its peers.