ATLANTA>> The Trump administration’s new vaccine advisers on Thursday endorsed this fall’s flu vaccinations for just about every American — but only if they use certain shots free of an ingredient that vaccine skeptics falsely have tied to autism.

What is normally a routine step in preparing for the upcoming flu season drew intense scrutiny after U.S. Health Secretary Robert F. Kennedy Jr. abruptly fired the influential 17-member Advisory Committee on Immunization Practices and handpicked replacements who include several vaccine skeptics.

The seven-member panel bucked another norm Thursday as it discussed the safety of a preservative used in less than 5% of U.S. flu vaccinations: It deliberated based only on a presentation from an antivaccine group’s former leader without allowing the public airing of scientific data from the Centers for Disease Control and Prevention.

The preservative, thimerosal, has long been used in certain vaccines that come in multidose vials, to prevent contamination as each dose is withdrawn. But it has been controversial because it contains a small amount of a particular form of mercury.

Study after study has found no evidence that thimerosal causes autism or other harm. Yet since 2001, all vaccines routinely used for U.S. children age 6 years or younger have come in thimerosal-free formulas — including single-dose flu shots that account for the vast majority of influenza vaccinations.

The advisory panel first voted, with one abstention, to back the usual U.S. recommendation that nearly everyone age 6 months and older get an annual flu vaccination. Then the advisers decided people should be given only thimerosal-free single-dose formulations, voting 5-1 with one abstention.

That would include single-dose shots that already are the most common type of flu vaccination, as well as the nasal spray FluMist. It would rule out the subset of flu vaccine dispensed in multidose vials.

The ACIP helps the CDC determine who should be vaccinated against a long list of diseases, and when. Those recommendations have a big impact on whether insurance covers vaccinations and where they’re available.

Normally the CDC’s director would decide whether to accept ACIP’s recommendation, but the Senate has not confirmed nominee Susan Monarez. Administration officials said Kennedy would make that decision.

Medical groups decried the panel’s lack of transparency in blocking a CDC analysis of thimerosal that concluded there was no link between the preservative and neurodevelopmental disorders, including autism. The data had been posted on the committee’s website Tuesday but was later removed; because, according to ACIP member Dr. Robert Malone, the report hadn’t been authorized by Kennedy’s office. Panel members said they had read it.

While Thursday’s debate involved only a small fraction of flu vaccines, some public health experts contend the discussion unnecessarily raised doubt about vaccine safety. Already, fewer than half of Americans get their yearly flu vaccinations, and mistrust in vaccines overall is growing.

“Selective use of data and omission of established science undermines public trust and fuels misinformation,” said Dr. Sean O’Leary of the American Academy of Pediatrics. He said of the new panelists, “Nothing about their recent actions have been science-based or transparent.”

The votes marked the final step of a two-day meeting that alarmed pediatricians and other doctors’ groups, who pointed to the new panelists’ lack of expertise in how to track vaccine safety and a shift in focus to someanti vaccine messages.

“What should have been a rigorous, evidence-based discussion on the national vaccine schedule instead appeared to be a predetermined exercise orchestrated to undermine the well-established safety and efficacy of vaccines and fundamental basics of science,” said Dr. Jason Goldman of the American College of Physicians.