A panel of scientific experts that advises the Food and Drug Administration on vaccine policy — and has been the target of criticism from Health Secretary Robert F. Kennedy Jr. — learned on Wednesday that its upcoming meeting to discuss next year’s flu vaccines has been canceled.
The F.D.A. sent an email to members of the Vaccines and Related Biological Products Advisory Committee on Monday afternoon informing them of the cancellation, according to a senior official familiar with the decision. There was no reason given. The panel was to meet March 13.
One committee member, Dr. Paul Offit of the Children’s Hospital of Philadelphia, an outspoken critic of Mr. Kennedy, confirmed the cancellation and warned that it could interfere with or delay production of flu vaccines.
“It’s a six-month production cycle,” Dr. Offit said. “So one can only assume that we’re not picking flu strains this year.”
The cancellation — and the postponement last week of a similar meeting of scientific advisers to the Centers for Disease Control and Prevention — plays into fears among scientists who worry that Mr. Kennedy will use his perch to sow doubts about vaccines and interfere with the regulatory process that leads to their approval.
Richard Hughes, a lawyer for some vaccine makers, said the postponement was concerning since the schedule for making the flu vaccine tends to be quite strict. Strains are usually selected in the F.D.A. meeting in February or March using data from the World Health Organization — a relationship the United States walked away from early in the Trump administration. He said manufacturing tends to begin in June.
“The stakes are incredibly high,” he said, noting that this year’s flu season has been especially intense.
According to the C.D.C., 86 children and 19,000 adults have died from flu this winter season. About 430,000 people were hospitalized. In June, a C.D.C. committee tends to decide whether to advise use of the vaccine, which sets in motion insurance and government coverage of the vaccines, Mr. Hughes said.
As a presidential candidate and more recently as a supporter of President Trump, Mr. Kennedy repeatedly warned of “regulatory capture” — the idea that federal regulators are captive to industry. He has said he intends to root out conflicts of interest on the scientific panels that advise federal regulatory agencies.
The members of those committees often team up with industry; Dr. Offit, for instance, is an inventor of a rotavirus vaccine that was developed by the pharmaceutical giant Merck. Committee members are currently required to declare their collaborations and recuse themselves from voting on issues in which they have a financial stake. Mr. Kennedy has suggested he wants more stringent restrictions.
The meeting of the C.D.C.’s Advisory Committee on Immunization Practices would have covered topics related to a number of vaccines, including one that protects against the human papillomavirus. Mr. Kennedy has been sharply critical of that vaccine.