Health Secretary Robert F. Kennedy Jr. announced a plan that would require placebo-controlled studies for all new vaccines, surprising some experts who noted that such testing already routinely takes place.
In a statement, Andrew Nixon, a spokesman for the Department of Health and Human Services, said that “all new vaccines will undergo safety testing in placebo-controlled trials” before approval, and called the move a “radical departure” from existing standards.
Even though modern studies routinely use placebos, one exception has been the Covid booster shots, which have been authorized without human trials to target new strains of the virus as it has evolved. It’s unclear how the announcement will affect availability of Covid vaccines that were expected to be updated for the fall.
Mr. Kennedy also announced an effort Thursday for the National Institutes of Health to turbocharge the development of new inoculations for Covid, bird flu and seasonal flu.
The new vaccine development initiative would involve methods other than the mRNA technology used to develop the dominant Covid vaccines that are already in use, a statement from the Health and Human Services department said. The mRNA shots have been the subject of conspiracy theories, and Mr. Kennedy has intensely criticized them.
Taken together, the moves suggest that Mr. Kennedy will reach far into the details of vaccine development, an effort likely informed by his decades as one of the nation’s most vocal critics of immunization oversight.
Though some scientists say the quest to fully understand the possible unanticipated effects of vaccines is worthwhile, they also warn that doing so in a way that delays approval of lifesaving shots could jeopardize public health.
Mr. Kennedy’s activism in recent years included petitioning the Food and Drug Administration to pull the Covid vaccine off the market in 2021, during a deadly phase of the pandemic. He also urged the F.D.A. not to authorize Covid shots for children.
Asked about how the new testing policy would affect Covid booster shots, Mr. Nixon suggested that new trials could be requested. Though the vaccines authorized by the F.D.A. were initially studied in large trials against placebos, Mr. Kennedy and others have criticized the lack of clinical trials for the boosters.
“As we’ve said before, trials from four years ago conducted in people without natural immunity no longer suffice,” Mr. Nixon said. “A four-year-old trial is also not a blank check for new vaccines each year without clinical trial data, unlike the flu shot which has been tried and tested for more than 80 years. The public deserves transparency and gold-standard science — especially with evolving products.”
Pfizer and Moderna, makers of the mRNA Covid shots, did not respond immediately to requests for comment. The Washington Post first reported the policy shift.
Dr. Ofer Levy, a Harvard vaccine researcher and a member of the F.D.A.’s vaccine advisory committee, said exploring possible unexpected effects from vaccines would be a valuable effort. But he said officials must “thread the needle” to be sure it is done in a way that did not leave older and immunocompromised people unprotected from Covid.
He said that leaving a group taking the placebo vulnerable to Covid posed ethical concerns that would need to be carefully considered. Holding up authorization for updated Covid shots would be “unacceptable,” he said.
“Tens of thousands of people can die without protection against Covid,” said Dr. Levy, who co-founded a company working on an opioid vaccine.
The Centers for Disease Control and Prevention reported about 23,000 deaths from Covid since September, with as many as 1,000 a week that month and in January. Still, uptake of the Covid boosters has been low: About 23 percent of adults got the updated Covid shot released in the fall, according to the C.D.C.
Mr. Kennedy’s familiarity with the issue stems at least in part from his reviews of decades-old vaccine approvals, including for the polio vaccine and the measles, mumps and rubella vaccine. He has also helped represent plaintiffs in lawsuits against manufacturers.
He and the organization he founded and once led, Children’s Health Defense, have repeatedly complained that vaccines are not tested against placebos in clinical trials when they are being developed. The organization has cited polio, hepatitis and meningitis vaccines as examples, all vaccines that were introduced decades ago.
“Every other medicine is tested against a placebo,” Mr. Kennedy said on a podcast in January 2020, in claiming that vaccines are exempt from that requirement.
That, however, is not entirely correct. Cancer drugs and other medications authorized under the F.D.A.’s accelerated approval program are regularly authorized after trials without a placebo. And new vaccines, including the vaccines for Covid, were tested against placebos — inert substances, such as a saline injection, or in some cases against vaccines for other diseases.
But new formulations of already approved vaccines are compared to those in existing vaccines in clinical trials, because it would be considered unethical to withhold effective vaccines from patients, including infants.
“We’ve required placebo-controlled trials for most vaccines, and sometimes it’s an inert placebo, and sometimes it’s an irrelevant vaccine,” said Dr. Peter Marks, who was the Food and Drug Administration’s top vaccine official until he was forced out in March. “The claim that we have not done randomized trials for pediatric vaccines aside from Covid is not correct.”
Mr. Kennedy has also raised concerns in the past about testing a vaccine against what many consider a reasonable placebo: the same formula, but without the immune-activating agents. Mr. Kennedy has noted that the practice leaves uncertainty about whether ingredients in the formula could cause harm.
The announcement that the National Institutes of Health will develop new technology for making flu and coronavirus vaccines to prevent against pandemics appears aimed at displacing the mRNA vaccine technology that has been a target of critics, including the health secretary.
This “next-generation vaccine platform” would be “fully government-owned,” the department said. The N.I.H. helped develop the mRNA platform, and the vaccine maker Moderna paid the government hundreds of millions of dollars to license a key patent on the vaccine, though the company and the government later got into a dispute over the patent rights.
The mRNA platform relies on small bits of genetic code, which generated online rumors and conspiracy theories that it was being used to insert microchips into vaccine recipients. The new platform, by contrast, would rely on a more traditional method of vaccine development, which uses inactivated viruses to provoke an immune response.
The department said the new platform would be developed using beta-Propilactone, which is already a component in vaccine development but is considered a hazardous substance by the Environmental Protection Agency when people are exposed to it in large doses.