United States Department of Health & Human Services mandates placebo testing for new vaccines; healthcare leaders warn policy will delay vaccine development, harm public confidence

May 2, 2025 (Chief Healthcare Executive) –

The federal government is planning to change the way vaccines are tested, and some health leaders say the new policy is troubling.

The U.S. Department of Health & Human Services is going to test new vaccines by comparing results against a placebo. The Washington Post , which first reported the policy change, says with new vaccines, some patients will receive the vaccine and others will receive a placebo, and the results will be compared.

The new policy marks another controversial step involving vaccines since U.S. Health & Human Services Secretary Robert F . Kennedy Jr. took control of the health department. Kennedy has been a longtime critic of vaccines and has repeatedly derided their safety and effectiveness.

Some healthcare leaders say the new policy could delay the development of vaccines and do more damage to public confidence in vaccines at a time when vaccination rates are declining. Some also argue it's not appropriate to give placebos when there are vaccines that have been tested and proven to be effective.

Ezekiel J. Emanuel , MD, vice provost of global initiatives at the University of Pennsylvania and a health policy adviser under former President Barack Obama , wrote in a post on LinkedIn that the policy is problematic.

"HHS requiring placebo-controlled trials for COVID and flu vaccines is deeply concerning - and unethical," Emanuel wrote. "Adding unnecessary layers of approval will make it practically impossible to implement in time for seasonal vaccines. This isn't about safety, as RFK Jr. claims; it's a thinly veiled attempt to undermine public health protections, putting millions at risk."

The new policy wouldn't apply to the flu vaccine, but it's not clear which vaccines would be required to be compared against placebo testing.

Paul Offit , director of the Vaccine Education Center at Children's Hospital of Philadelphia , said the new policy could make it more onerous to develop more vaccines. Offit told the Post, "The goal is to make vaccines less available and less affordable."

In a statement to the Post, the health department said that with the exception of the COVID vaccine, none of the vaccines recommended for children by the CDC was tested against a placebo, "meaning we know very little about the actual risk profiles of these products."

Peter Hotez , MD, professor and dean of the national school of tropical medicine at Baylor College of Medicine , disputed contentions - including those from the health department - that childhood vaccines weren't already tested in placebo-controlled trials.

"That's simply not true," Hotez wrote in a post on X. He also listed such studies, including research of measles, mumps and rubella vaccines, polio, and others, and links to research showing they had previously been tested against placebos.

Lawrence Gostin , faculty director of Georgetown University's O'Neill Institute for National and Global Health, also rejected claims that new vaccines aren't tested against placebos.

"Many vaccines trials are randomized placebo controlled. But placebos can be unethical when there is a known proven vaccine that can prevent a dangerous disease. Kennedy ignores the nuance & pursues his pet peeves," Gostin wrote in a post on X.

In March, the Centers for Disease Control & Prevention said it would undertake a study to examine any links between vaccines and autism, even as previous studies have found no such link exists. Healthcare leaders say such studies waste resources at a time when the government is cutting spending and could weaken confidence in vaccines. Critics also criticized the choice of David Geier , a vaccine skeptic, to lead the study.

Sen. Bill Cassidy , a Louisiana Republican and a physician, said he secured a commitment from Kennedy and the White House that vaccine protocols wouldn't be changed without overwhelming scientific evidence. A physician, Cassidy said that commitment was a key in supporting Kennedy's confirmation.

In a speech on the Senate floor in February, Cassidy said, "He has also committed that he would work within the current vaccine approval and safety monitoring systems, and not establish parallel systems."

Kennedy has encouraged people to get the measles vaccine in the wake of an outbreak that has seen far more cases than last year, but critics have said he should be more outspoken about the need for vaccination.