A key US vaccine advisory committee has voted to stop recommending all adults get the Covid-19 vaccine, which has until now been officially approved for most Americans annually since the pandemic.

The Advisory Committee on Immunization Practices (Acip) also narrowly voted against advocating prescriptions for the Covid vaccine.

In two days of meetings, Acip changed its recommendations on the combined measles, mumps, rubella, varicella (MMRV) vaccine, and delayed plans for a vote on the hepatitis B vaccine.

Health Secretary Robert F Kennedy Jr, a vaccine sceptic, fired all 17 members of the committee in June and handpicked their successors, sparking uproar in the medical community.

The panel spent Friday debating the Covid-19 vaccine, which has for the past several years been a routine recommendation, like the yearly flu jab. Acip voted to abandon broad support for recommending the jab, including for high-risk populations like people aged over 65. Instead, it decided they could make their own decision after talking with a medical professional.

In May, the federal government stopped recommending Covid-19 vaccines for healthy pregnant women and children. In a debate, Kennedy's ally Dr Robert Malone argued there was no evidence that the Covid vaccine prevented serious infection, while Dr Cody Meissner countered that there is pretty well-defined data supporting its protective effects.

Confusion arose regarding the MMRV vaccine, after the panel voted against recommending it for children aged four and under but later endorsed two separate jabs for measles, mumps and rubella, and varicella.

The American Medical Association expressed concerns that the new MMRV recommendations leave parents confused.

Additionally, the panel delayed a vote on whether newborns whose mothers have tested negative for hepatitis B during pregnancy should automatically receive a jab for the virus. Acip has raised doubts about the hepatitis B vaccine, despite scientific consensus on its safety and effectiveness.

Robert F Kennedy Jr's posture on vaccinations has drawn scrutiny since he took office. He has overhauled the CDC during his tenure, replacing advisory panel members and igniting debate over vaccine policy. In recent testimonies, former panel members cited concerns over changing vaccine policies against scientific evidence.