Statements from a federal official about potential changes to the way vaccines are evaluated have left experts with more questions than answers.
Earlier this month, an apparent policy change appeared in a statement to the Washington Post in which an HHS spokesperson told the paper that “All new vaccines will undergo safety testing in placebo-controlled trials prior to licensure — a radical departure from past practices.” The statement confused experts who said that vaccines aimed at new pathogens have always been tested this way.
“That has been true of every new vaccine, ever,” Paul Offit, MD, of Children’s Hospital Philadelphia, told MedPage Today. “I can’t think of a single vaccine in the United States that was truly a new vaccine — not an improvement on an existing vaccine, in which case you have to test it against the existing vaccine — that has not been subjected to placebo control.”