A resurfaced video of RFK Jr. from 2023 shows him falsely linking the polio vaccine to other diseases. Ari Melber fact checks the heath secretary's claims.

The 17 members of the CDC's vaccine advisory committee, who were ousted last week, argued their abrupt dismissal has "left the U.S. vaccine program critically weakened."

A senior scientist at the U.S. Centers for Disease Control and Prevention has resigned, warning that changes in leadership may weaken the country's vaccine program.