U.S. health officials knew about the risks of myocarditis from COVID-19 vaccines but downplayed the concern and delayed ...

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.

A previous federal policy recommended an annual COVID shot for all Americans six months and older. Here is what the new proposal would be.

For groups younger than 65 or without specific chronic conditions, postmarketing trials will be needed to open access.