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.

One of the Centers for Disease Control and Prevention’s top vaccine specialists has warned that Robert F. Kennedy Jr.’s anti-vax policies will cause “a lot of Americans to die” after resigning from the agency on Monday.

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."