Heart protection from COVID shots remains amid updates, study finds

# Heart protection from COVID shots remains amid updates, study finds Source: [https://arstechnica.com/health/2026/06/covid-vaccines-still-protect-against-heart-problems-large-study-finds/](https://arstechnica.com/health/2026/06/covid-vaccines-still-protect-against-heart-problems-large-study-finds/) Although most Americans have eschewed seasonal COVID\-19 vaccines, the updated shots continue to show significant protection against cardiovascular disease, especially for those over age 75 and those with underlying medical conditions\. That’s according to[a new study](https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2850241)that pulled data from more than 1 million patients in a US Department of Veterans Affairs \(VA\) health system\. The finding builds on previous data showing that the vaccines significantly lower the risk of COVID\-19\-associated cardiovascular risks, particularly heart attacks and strokes\. But it wasn’t a given that the benefit would hold up over time—as the virus evolved, the vaccines were updated, population\-level immunity increased from previous infection and vaccination, and risk of severe outcomes fell\. The new study, published in JAMA Internal Medicine, found that the 2024–2025 COVID\-19 vaccine continued to protect against COVID\-19\-associated “major adverse cardiovascular events” \(MACE\), which include cardiovascular death, heart attack, stroke, and hospitalization for heart failure\. The study included electronic medical record data from 1,039,659 patients in the VA’s St\. Louis Health Care System\. All of the patients received a seasonal flu shot between September 3, 2024, and December 31, 2024, with some also getting a COVID\-19 vaccine at the same time\. Of the 1,039,659 patients, 349,085 received both shots, while 690,574 got just the flu shot\. The latter group acted as the control group for the study\. After eight months of follow\-up, the researchers looked for documented COVID\-19 cases and compared MACE events among the two groups\. Overall, the COVID shots’ vaccine effectiveness against MACE events was 38 percent\. In terms of absolute numbers, the benefit is modest\. The study estimated that the shots dropped the rate of COVID\-19\-associated MACE events from about 5 in 10,000 to 3 in 10,000\. Looking across subgroups, the benefits were strongest among those aged 75 and older and those with underlying health conditions\.