Updated COVID-19 vaccines offer significant protection against cardiovascular disease. This protection is especially notable for individuals over 75 and those with pre-existing medical conditions. These findings come from a new study analyzing data from over one million patients in a United States Department of Veterans Affairs (VA) health system.
The study's results reinforce earlier data. Previous research indicated that COVID-19 vaccines reduce the risk of cardiovascular issues linked to the virus, such as heart attacks and strokes. The recent study confirms these benefits persist even as the virus evolves and vaccines are updated.
Published in JAMA Internal Medicine, the research focused on the 2024–2025 COVID-19 vaccine. It found continued protection against major adverse cardiovascular events (MACE) associated with COVID-19. MACE includes cardiovascular death, heart attack, stroke, and hospitalization for heart failure.
The study utilized electronic medical records from 1,039,659 patients within the VA's St. Louis Health Care System. All participants received a seasonal flu shot between September 3 and December 31, 2024. A subset of 349,085 patients received both the flu shot and a COVID-19 vaccine. The remaining 690,574 patients, who received only the flu shot, served as a control group.
After an eight-month follow-up, researchers observed documented COVID-19 cases and compared MACE events between the two groups. The COVID-19 shots demonstrated a 38 percent effectiveness against MACE events. The benefits were most pronounced in individuals aged 75 and older and those with underlying health conditions. An accompanying study in JAMA Internal Medicine also reported that the vaccines directly protect against COVID-19, reducing hospitalization risk by 35 percent and critical illness risk by 41 percent.
Robert Califf, a cardiologist and former Food and Drug Administration (FDA) commissioner, wrote an accompanying editorial. He stated that the studies provide strong evidence of a favorable benefit-to-risk balance for updated COVID-19 vaccine boosters across the population. Federal data indicates that only 17.5 percent of adults and 22.6 percent of individuals over 65 in the U.S. have received the 2025–2026 COVID-19 shot.
Related stories
Glassblowing Revolutionized Daily Life in Ancient Rome
The invention of glassblowing in the late first century BCE dramatically changed daily life in ancient Rome by making glass objects affordable and widely accessible.
New Membrane Technology Offers Precise Molecular Filtration
Scientists developed a new membrane with one-nanometer pores, potentially cutting industrial energy use and improving water recycling and chemical purification.
Bipartisan Bill Aims to Curb Government Coercion of Tech Platforms
Senators Ted Cruz and Ron Wyden introduced the bipartisan JAWBONE Act to prevent federal officials from coercing tech platforms and broadcasters into censoring content, allowing individuals to sue for damages.