A major new analysis published in the Journal of the American Heart Association is shedding light on how viral infections — including Covid-19, influenza, HIV, hepatitis C, and shingles — can significantly increase a person’s risk of developing cardiovascular disease (CVD), including heart attacks and strokes.
The study, which reviewed findings from 155 different studies conducted over several decades, found a consistent and concerning link between viral infections and cardiovascular complications. Researchers concluded that both acute viral infections (short-term illnesses like the flu or Covid-19) and chronic infections (long-lasting ones like HIV or hepatitis C) are associated with a heightened risk of heart problems — not only immediately after infection but sometimes for years afterward.
Short-Term and Long-Term Risks
According to the researchers, people who contracted the flu were up to six times more likely to experience a heart attack within one month after the infection compared with those who didn’t catch the flu. Likewise, individuals infected with Covid-19 were found to be nearly twice as likely to develop heart disease or stroke compared with people who had not been infected with the virus.
Dr. Kosuke Kawai, adjunct professor at the David Geffen School of Medicine at UCLA and lead author of the study, explained that while the connection between infection and heart disease may surprise many, the science behind it is becoming increasingly clear.
“One way to prevent this is really vaccination,” said Dr. Kawai. “Often, we get vaccinated to reduce the risk of influenza or other illnesses, but vaccines can provide additional benefit in terms of potentially protecting against cardiovascular disease.”
How Viral Infections Impact the Heart
The researchers noted that the mechanism by which viruses impact cardiovascular health can vary. For example, respiratory infections like Covid-19, influenza, and RSV (respiratory syncytial virus) typically trigger an indirect inflammatory response in the body. When the immune system becomes overactive, it releases chemicals that cause inflammation and clotting, placing stress on the heart and blood vessels.
Dr. Scott Roberts, associate medical director for infection prevention at Yale School of Medicine, explained that this immune overreaction can be dangerous.
“Respiratory viruses increase cardiovascular risk in two ways — indirectly, by causing inflammation and stress that can lead to blood clotting, and directly, when certain viruses infect heart tissue themselves,” Roberts said.
He noted that while most respiratory viruses act through the indirect pathway, some viruses, such as enteroviruses (related to those that cause hand, foot, and mouth disease), can directly infect the heart muscle, leading to conditions like myocarditis (inflammation of the heart muscle).
“Generally, the more severe the viral illness, the greater the risk of cardiovascular complications,” Roberts added. “Even mild infections can sometimes trigger a cardiovascular event in people who already have underlying heart disease.”
Broader Viral Connections
The study didn’t stop at just Covid-19 and influenza. It found that chronic viral infections — like HIV, hepatitis C, and shingles — were associated with a long-term increase in the risk of coronary heart disease and stroke. These infections can cause ongoing inflammation and immune system activation, which over time may damage arteries, increase plaque buildup, and strain the heart.
In addition, researchers cited evidence linking cytomegalovirus (CMV), herpes simplex virus (HSV), hepatitis A, human papillomavirus (HPV), respiratory syncytial virus (RSV), dengue, and chikungunya with increased cardiovascular risk. However, they noted that more research is still needed to establish the exact mechanisms for these associations.
Dr. Kawai emphasized that it’s not only older adults or people with existing health problems who are at risk.
“It’s not just patients who have underlying cardiovascular conditions,” he said. “Younger adults or people who might not necessarily have traditional risk factors for heart disease are also at increased risk after viral infections.”
Why Prevention Matters
Cardiovascular disease remains the leading cause of death worldwide, and understanding how viral infections contribute to it could have enormous implications for public health. The researchers stressed that prevention and early intervention can make a significant difference — and vaccination is one of the most effective tools available.
“Our study highlights the importance of integrated preventive measures, especially for adults with traditional risk factors for cardiovascular disease,” the authors wrote. “Vaccines may play an important role in preventing the risk of CVD.”
Vaccines for viruses such as influenza, Covid-19, HPV, and hepatitis B are already available and can help prevent not just the infections themselves but potentially the secondary cardiovascular complications that may follow.
Dr. Roberts agreed, noting that vaccinated individuals typically experience milder infections, which lowers the strain on the cardiovascular system.
“Vaccines for many of these viruses exist and generally lessen the risk of cardiovascular events after infection, since a vaccinated person’s illness tends to be less severe,” Roberts said.
Are Vaccines Safe for the Heart?
Both experts emphasized that vaccines are safe and do not cause cardiovascular disease. The immune response triggered by a vaccine is controlled and temporary, unlike the overactive inflammatory reaction that can occur during a severe viral infection.
Dr. Kawai explained that most vaccines use inactivated viruses or specific viral subunits, meaning they cannot infect the body or harm heart tissue. Instead, they train the immune system to recognize and fight the virus without causing excessive inflammation.
“The inactivated virus in vaccines does not trigger the kind of overactive immune response that damages the heart,” Kawai said. “That’s why vaccination is such a key protective strategy.”
The Takeaway
This research offers strong evidence that viral infections should not be underestimated when it comes to heart health. Even after recovery, the effects on the cardiovascular system can linger. The study’s authors suggest that clinicians and patients alike should consider viral infection history as a potential risk factor when evaluating cardiovascular health.
The message is clear: preventing infections may also prevent heart disease. Regular vaccination, timely antiviral treatments, and awareness of post-infection symptoms can help reduce both short-term and long-term heart complications.
Dr. Roberts advises anyone who recently had a viral infection — especially if they experience chest pain, shortness of breath, or fatigue — to consult a doctor immediately.
“Anyone concerned about the risk of heart problems after an infection should talk with their physician,” Roberts said. “Early evaluation can make all the difference.”
As researchers continue to study how viruses interact with the cardiovascular system, one thing is certain: staying protected against infections doesn’t just keep you from getting sick — it could also save your heart.
Source: Journal of the American Heart Association
Disclaimer: This article is for informational purposes only. It should not be taken as medical advice. Always consult a qualified healthcare professional regarding vaccines, infections, or cardiovascular health.