The FDA is requiring COVID vaccine makers Pfizer and Moderna to update their warnings about the possible risk of myocarditis and pericarditis.

Top health officials were aware of and actively took steps to “delay warning the public” for months in 2021 about the potential risks of patients suffering from heart-related ...

This week, mRNA vaccines are set to face intense scrutiny from critics in Congress. Here's an explainer of how we know they are safe and effective.