Overview
- A JAMA Internal Medicine analysis of 1,039,659 U.S. Veterans found receipt of the 2024–2025 COVID vaccine with a flu shot was associated with about a 38–40% relative reduction in COVID‑associated major adverse cardiovascular events.
- The absolute benefit was modest, equal to roughly 2–5 fewer heart attacks, strokes, or cardiovascular deaths per 10,000 people over eight months of follow‑up.
- Because the study is observational rather than randomized, authors and outside experts warn the result shows association not proof of causation and could be affected by unmeasured confounding or undetected infections.
- The VA cohort skews older and male, which limits generalizability, and experts say the likely mechanism is vaccination preventing infections that trigger blood‑vessel inflammation and later heart problems.
- Cardiologists are using the findings to push back on social‑media vaccine myths and to call for randomized trials and clearer public messaging, while Indian health experts say the paper does not justify a change in India’s vaccine policy given different vaccine use and current low COVID complication rates.