Winter Respiratory Viruses and Their Link to Heart Attacks and Strokes: Why Vaccination Is Key

As winter arrives, bringing colder weather and a rise in respiratory illnesses, concerns extend beyond just the common cold or flu. Emerging research highlights how seasonal viruses such as influenza and COVID-19 can significantly increase the risk of heart attacks and strokes, especially during this time of year.

Studies suggest that infections from respiratory viruses can act as triggers in individuals already vulnerable due to traditional risk factors like high cholesterol, high blood pressure, obesity, diabetes, and aging. These viruses may not directly cause heart attacks or strokes but can set off an inflammatory chain reaction that destabilizes existing plaques in blood vessels, leading to clots and vascular blockages.

A comprehensive meta-analysis examining over 11,000 scientific papers spanning four decades found that catching the flu increases the short-term risk of a heart attack by approximately fivefold and the risk of stroke by nearly five times. COVID-19 infection also appears to elevate these risks, although the precise extent remains under investigation. Other viruses, such as RSV, enteroviruses, and cytomegaloviruses, are also linked to increased cardiovascular events, albeit to a lesser degree.

The process involves viral infection-induced inflammation damaging vulnerable blood vessel plaques. This triggers blood clot formation, which can obstruct blood flow, resulting in a heart attack or stroke. Fragments of the COVID virus have even been identified inside blood clots, further supporting this connection.

Given these findings, vaccination emerges as a vital preventive measure. Evidence from clinical trials indicates that flu vaccines significantly reduce the risk of cardiovascular events, especially in people with existing heart conditions. COVID vaccines may offer similar benefits by decreasing the severity or likelihood of infections that can activate harmful inflammation.

Preventative actions are particularly crucial for older adults and those with pre-existing health issues, as they are more susceptible. It is recommended that at-risk groups receive annual flu and COVID vaccines, and older individuals or those with medical conditions should also consider RSV vaccination.

Adopting a healthy lifestyle—regular exercise, balanced diet, and managing risk factors—remains essential for everyone. Maintaining heart health through these measures, combined with vaccination, can substantially reduce the risk of severe cardiovascular events during the winter virus season.