Updated COVID vaccines reduce heart risks even in high-risk groups

A landmark study analyzing data from more than one million patients across the U.S. Department of Veterans Affairs health system confirms that updated COVID-19 vaccines continue to provide strong protection against cardiovascular complications. Published in JAMA Internal Medicine, the research highlights that the 2024–2025 vaccine formulation remains effective in reducing major adverse cardiovascular events (MACE), including heart attacks, strokes, cardiovascular death, and hospitalizations due to heart failure.

Vaccines maintain efficacy despite evolving virus and immunity

While prior studies demonstrated that COVID-19 vaccines significantly lower the risk of virus-associated heart problems, researchers questioned whether this protection would persist as the virus mutated, immunity waned, and population-level defenses strengthened through prior infections and vaccinations. The updated findings address these concerns, showing that the 2024–2025 vaccine still delivers measurable cardiovascular benefits.

The study’s authors analyzed electronic health records from the VA system, focusing on adults who received the latest vaccine dose between September 2024 and March 2025. The cohort included individuals with pre-existing health conditions such as diabetes, hypertension, and chronic respiratory diseases—groups historically at higher risk for severe COVID-19 outcomes. Even in these vulnerable populations, the vaccine demonstrated a protective effect against MACE, particularly among adults aged 75 and older.

Key takeaways from the research

• Broad protection: The vaccine reduced the risk of major cardiovascular events by approximately one-third in fully vaccinated individuals compared to unvaccinated peers.
• Age matters: The protective effect was most pronounced in individuals over 75, where the risk reduction exceeded 40% for MACE.
• Chronic conditions: Patients with underlying health issues, such as heart disease or diabetes, saw a 25% lower risk of cardiovascular complications post-vaccination.
• Real-world data: The study leveraged a vast dataset, ensuring the findings reflect real-world effectiveness rather than controlled trial conditions.

Why cardiovascular protection remains critical

COVID-19 has been linked to a range of cardiovascular complications, from myocarditis to long-term heart damage, even in mild cases. While the overall severity of the virus has declined, the study underscores the importance of vaccination for high-risk groups. The research suggests that updated vaccines not only prevent severe illness but also mitigate long-term health burdens associated with the virus.

Public health experts emphasize that vaccination remains a cornerstone of protection, particularly as new variants emerge and immunity wanes. The study’s lead author noted that the findings reinforce the need for continued vaccine updates to match circulating variants, ensuring sustained efficacy against both infection and complications.

As the medical community continues to refine vaccine strategies, this research provides reassurance that current formulations are still a vital tool in safeguarding heart health, especially for those most vulnerable to severe outcomes.