Study Highlights Cardiovascular Benefits of COVID-19 Vaccines, Despite Low Booster Uptake

A new study published in *JAMA Internal Medicine* underscores the cardiovascular protection offered by COVID-19 vaccines, even in individuals without documented infections, according to research led by Ziyad Al-Aly, an epidemiologist at the St. Louis VA. The findings suggest that vaccines reduced the risk of major adverse cardiovascular events (MACE) and deaths, with benefits more pronounced in cases where COVID-19 was undiagnosed.

The study analyzed data from U.S. veterans, a population predominantly older, white, and male, and found that vaccination lowered MACE rates from 382 to 358 per 10,000 individuals and death rates from 223 to 207 per 10,000. Researchers estimated that vaccinating 1 million people could prevent approximately 2,370 MACE events and 1,580 deaths over eight months. However, they cautioned that the results may not apply broadly due to the demographic limitations of the veteran population.

Why Do Vaccines Offer Cardiovascular Protection?

The study’s authors attribute the cardiovascular benefits to vaccines’ ability to reduce inflammation and clotting risks linked to COVID-19, even in asymptomatic cases. An accompanying analysis in the same journal found that vaccines reduced hospitalizations and critical illness by 35% and 41%, respectively.

Robert Califf, a cardiologist and former FDA commissioner, emphasized the “favorable balance of benefit to risk” for updated boosters in an editorial. He criticized the “general antivaccination statements” from the U.S. Department of Health and Human Services, which he said have undermined public trust. Califf noted that only 17.5% of adults and 22.6% of those over 65 had received the 2023–2024 COVID-19 shot, according to federal data.

What Are the Study’s Limitations?

The research primarily focused on veterans, a group with unique health profiles, raising questions about its applicability to younger or more diverse populations. Additionally, the study could not fully account for undiagnosed cases, which may have skewed results. Experts stress that while the findings support vaccination, more data is needed to confirm long-term benefits across broader demographics.

How Does This Impact Public Health Policy?

Califf called for increased public engagement to counter anti-vaccine misinformation, particularly on social media. He argued that the politicization of vaccines has “taken a toll on the longevity and functional status of those in the U.S.” The study adds to growing evidence that vaccines remain critical in preventing severe outcomes, even as booster uptake lags.

What’s Next for Vaccine Research?

Researchers are urging further studies to explore the vaccines’ effects on non-COVID-19 related outcomes and to address disparities in vaccination rates. The findings highlight the need for targeted communication strategies to reassure hesitant populations, especially as new variants and booster recommendations emerge.

Study details | Vaccination rate data | FDA information