Flu Vaccine May Hold Key to Preventing Heart Disease

Flu vaccines are known to have a protective effect against heart disease, reducing the risk of a heart attack. For the first time, this research, published in Vaccine, reveals the molecular mechanism that underpins this phenomenon. The scientists behind the study say it could be harnessed to prevent heart disease directly.

Heart disease is the leading cause of death worldwide. People can reduce their risk of heart disease by eating healthily, exercising and stopping smoking. However, to date there is no vaccine against heart disease.

Previous clinical findings show that people that receive the seasonal flu vaccine also benefit from its protective effect against heart disease; the risk of having a heart attack in the year following vaccination is 50% lower than people who did not receive the vaccination. The exact mechanism underlying this protective effect remained unknown.

This new study for the first time reveals this mechanism, showing that the flu vaccine stimulates the immune system to produce antibodies that switch on certain processes in cells. These processes lead to the production of molecules that protect the heart. The researchers say that based on the results it may be possible to develop a new vaccine against heart disease.

"Even though the protective effect of the flu vaccine against heart disease has been known for some time, there is very little research out there looking at what causes it. Our proposed mechanism could potentially be harnessed in a vaccine against heart disease, and we plan to investigate this further," said Dr. Veljkovic, Institute Vinca, Belgrade, the lead author of the new study.

The researchers identified a protein called the bradykinin 2 receptor (BKB2R), which is involved in cellular processes that protect the heart. Some of the antibodies the body produces after flu vaccination switch this protein on, therefore protecting against heart disease. The researchers analysed 14 flu viruses used in vaccines, and identified four that could be investigated for use in potential heart disease vaccines.

Flu shots: Especially important if you have heart disease

If you have heart disease, flu season can be a dangerous time. Death from influenza (flu) is more common among people with heart disease than among people with any other chronic condition. Fortunately, getting a flu shot can reduce your risk of catching the flu or developing complications from the flu.

Doctors have long recommended that older adults and other high-risk groups get flu shots, but they now emphasize the importance of flu shots for those with heart disease. The flu shot could prevent thousands of flu-related complications and deaths every year in people who have heart disease.
Why are flu shots important for those with heart disease?

Flu seasons vary from year to year in length and severity. For this and other reasons, it's not possible to know how many flu-related deaths occur. The Centers for Disease Control and Prevention estimates a range of flu-related deaths in the thousands annually in the United States. The rate of flu-related complications is even higher among people with heart disease.