Recently fired members of a committee that advises the federal government on immunization safety lashed out at Health and Human Services Secretary Robert F. Kennedy Jr., saying that their terminations will limit access to vaccines and put American lives at risk.

Robert F. Kennedy Jr.’s actions at the CDC “put U.S. families at risk of dangerous and preventable illnesses,” they say.

Fiona Havers, who oversaw CDC respiratory virus data, told colleagues she no longer had confidence the data would be used objectively to set vaccine policy.