Multiple Massachusetts-based vaccine companies, including Moderna, are affected by U.S. Health and Human Services Secretary Robert F. Kennedy, Jr.'s announcement ending federal support for mRNA ...

This week, U.S. Health Secretary Robert F. Kennedy Jr., a longtime vaccine critic, canceled $500 million in government-funded research projects to create new mRNA vaccines.

Health and Human Services Secretary Robert F. Kennedy Jr. said this week that he's pulling the plug on nearly $500 million in funding for the development of mRNA vaccines. Here's how they work.