Large study links recent Covid vaccination to fewer cardiac events
Recent Covid vaccination was associated with substantially lower rates of heart problems in a study published June 15 in JAMA Internal Medicine . Among more than 1 million veterans who received flu shots at Veterans Affairs facilities in 2024 — about a third of whom also got a Covid vaccine — vaccinated individuals had roughly a 38% lower risk of Covid-associated major cardiovascular events and a nearly 24% lower risk of cardiac events from any cause. The effect was largest in adults 75 and older and people with chronic illness.
The work, led by Ziyad Al-Aly of Washington University in St. Louis, is observational, so it cannot prove the vaccine caused the lower event rate; people who seek out vaccination may differ in ways that also protect their hearts. The authors also note that limited testing makes some Covid infections hard to identify, which complicates attributing each cardiac event. Even so, the scale of the apparent benefit — the authors estimate prevention of about 3,500 major cardiac events and 2,400 deaths per million people — adds to evidence that the cardiovascular risks of Covid infection outweigh the rare inflammatory side effects linked to the vaccine itself.