COVID-19 vaccines can trigger heart inflammation
Stanford Medicine researchers say they have identified the biological chain of events that can lead to rare cases of myocarditis after mRNA COVID-19 vaccination, Qazinform News Agency correspondent reports, citing Stanford Medicine.
Stanford scientists explain what happens inside the body when a small number of people-mainly young men-develop temporary heart inflammation after receiving an mRNA COVID-19 vaccine. Their research outlines how the immune system can, in rare situations, overreact and briefly irritate heart tissue.
The team compared blood samples from vaccinated individuals who developed myocarditis with samples from those who did not. They found two immune signals that consistently stood out in those who had the condition. These signals are normally used by the body to coordinate defenses against viruses, but in excess they can cause unwanted inflammation.
To understand this process better, the researchers recreated the reaction in the lab. They showed that one type of immune cell releases the first signal after exposure to the vaccine. That signal then activates another type of immune cell, which releases the second signal. Together, these two substances can irritate heart cells and attract more immune cells to the area, amplifying the inflammation.
Tests in mice and in lab-grown clusters of human heart cells confirmed the same pattern. When the two immune signals were blocked, signs of heart irritation dropped sharply, while the overall vaccine response remained largely intact.
The study also explored a potential protective measure. The team investigated a soy-based compound called genistein, known for its mild anti-inflammatory properties. In their experiments, genistein reduced the impact of the two immune signals and helped protect heart tissue. The form used in the study was a purified version, stronger than what is found in food or standard supplements.
Cardiologist Joseph Wu, who led the work, stressed that myocarditis after mRNA vaccination remains rare and usually resolves quickly. He also noted that COVID-19 itself is far more likely to trigger myocarditis than vaccination and carries many additional health risks.
The findings could help guide the design of future mRNA vaccines and offer clues about similar inflammatory reactions in other organs.
Earlier, Qazinform News Agency reported that mRNA COVID-19 vaccines show potential to boost cancer treatment.
