Sen. Susan Collins (R-Maine) on Monday called Health and Human Services Secretary Robert F. Kennedy Jr.’s firing of all 17 experts on the U.S. Centers for Disease Control and Prevention’s (CDC) vaccine panel “excessive,” but she cautioned she needs to learn more about the decision.

Kennedy announced the decision in an op-ed for The Wall Street Journal, catching many GOP lawmakers by surprise.

“I did not know that that had happened,” Collins, a senior member of the Senate Health, Education, Labor and Pensions (HELP) Committee, said. “It seems to me to be excessive to ask for everybody’s resignations, but I can’t judge because I don’t know who he’s replacing them with.”

The Maine senator said the CDC’s vaccine advisory committee “provided helpful guidance to the public on what they should do.”

Collins said that Kennedy didn’t promise members of the HELP Committee that he would keep the vaccine experts in place.

“I’m just learning about it for the first time,” she said. “I don’t know what the basis was.”

Kennedy said in his Wall Street Journal column that he removed the experts so that President Trump could shape the membership of the committee.

“Without removing the current members, the current Trump administration would not have been able to appoint a majority of new members until 2028,” he wrote.

Kennedy argued that vaccines have become “a divisive issue in American politics’ and that public confidence is waning” in health agencies, pharmaceutical companies and vaccines themselves.

“That is why, under my direction, the U.S. Department of Health and Human Services is putting the restoration of public trust above any pro- or antivaccine agenda. The public must know that unbiased science guides the recommendations from our health agencies. This will ensure the American people receive the safest vaccines possible,” he wrote.

Senate Democratic Leader Chuck Schumer (N.Y.) in a statement blasted Kennedy’s move as “reckless.”

“RFK Jr. and the Trump administration are taking a wrecking ball to the programs that keep Americans safe and healthy. Firing experts that have spent their entire lives protecting kids from deadly disease is not reform — it’s reckless, radical, and rooted in conspiracy, not science,” Schumer said in a statement.