Health Secretary Robert F Kennedy Jr's new vaccine advisers have confusion to COVID-19 vaccination season by declining to recommend them for anyone and leaving the choice up to those who want a shot.

Until now, the vaccinations had been recommended as a routine step in the autumn for nearly all Americans - just like a yearly flu vaccine.

The Food and Drug Administration already had placed new restrictions on 2025's shots from Pfizer, Moderna and Novavax, reserving them for people over 65 or younger ones who are deemed at higher risk from the virus.

In a series of votes on Friday, advisers to the Centers for Disease Control and Prevention took the unprecedented step of not recommending them even for high-risk populations like seniors.

Instead, they decided people could make individual decisions after talking with a doctor, nurse or pharmacist.

The panel meeting in Chamblee, Georgia, also urged the CDC to adopt stronger language around claims of vaccine risks, despite pushback from outside medical groups who said the shots had a proven safety record from the billions of doses administered worldwide.

The divided panel narrowly avoided urging states to require a prescription for the shot.

The meeting represented the latest example of Kennedy's months-long effort to reshape the nation's vaccine policies to match his longstanding suspicions about the safety and effectiveness of well-established shots.

Independent public health experts reacted with relief that the panel did not add more roadblocks to vaccination, but they said the lack of a recommendation would prove confusing for people who did not know if a shot might benefit them.

"The good news is anyone can get this vaccine. The bad news is that no one is encouraged to get it even if you're in a high-risk group," said Dr Paul Offit, a Children's Hospital of Philadelphia vaccine researcher and former government adviser who has sparred with Kennedy for years.

Dr Sean O'Leary of the American Academy of Pediatrics said the panel's day-long debate involved clear efforts to sow distrust about vaccines that would have "real-time impacts on American children".

But he said people could instead follow guidelines from his and other medical groups that still made specific recommendations for the vaccines.

Several states have announced policies to try to assure that access, and a group representing most health insurers, America's Health Insurance Plans, said its members would continue covering the shots through 2026.

The panel's decision still must go to the CDC's interim director, Jim O'Neill, for sign-off.

A former investor, critic of health regulations and Kennedy's deputy at HHS, O'Neill recently took the lead at the agency following the firing of its director, Susan Monarez.

COVID-19 remains a public health threat. CDC data released in June shows the virus resulted in 32,000 to 51,000 US deaths and more than 250,000 hospitalisations last autumn and winter.