The environmental activist Robert F. Kennedy Jr., a vaccine skeptic, told reporters Tuesday in the lobby of Trump Tower that the president-elect has asked him to lead a commission “to make sure we have scientific integrity in the vaccine process for efficacy and safety effects.” Mr. Kennedy also suggested that Donald Trump “has some doubts about the current vaccine policies” and that “we ought to be debating the science.” This is insane.

Mr. Kennedy in the past has raised doubts about thimerosal, a mercury-containing preservative...