WASHINGTON, D.C. — The head of the US public health agency has stepped down after just four weeks on the job, health officials announced Wednesday without explaining her departure, which follows the Trump administration's shift toward vaccine skepticism.

"Susan Monarez is no longer director of the Centers for Disease Control and Prevention. We thank her for her dedicated service to the American people," the Department of Health, which oversees the CDC, said in a curt statement on X.

Monarez, a health scientist and long-time civil servant, earned US Senate confirmation to the job and was then sworn in by Health Secretary Robert F Kennedy Jr on July 31.

The Washington Post, which first reported Monarez's dismissal, said she had refused to commit to supporting changes in vaccination policy sought by Kennedy, who is known for his vaccine skepticism.

According to officials who spoke on condition of anonymity, Monarez was pressured to resign by the health secretary.

The department did not immediately respond to AFP requests for comment on the reports.

Since taking office, RFK Jr, as he is known, has initiated a sweeping overhaul of US vaccine policy, dismissing renowned immunization experts, restricting access to Covid-19 shots, and slashing funding for the development of new vaccines.

Head of main US health agency abruptly dismissed, This news data comes from:http://www.erlvyiwan.com

Such measures are predominantly against scientific consensus, and have been criticized by outside experts.

The White House in March had to abandon President Donald Trump's first nominee as CDC head, David Weldon, a doctor known for his anti-vaccine stance, for fear he would not receive sufficient Senate support for confirmation.

The Monarez departure comes amid a crisis at the Atlanta-based CDC, which was the target of an armed attack in early August by a man who reportedly blamed the Covid vaccine on an unspecified illness.

Hundreds of health agency employees and former employees subsequently signed an open letter condemning Kennedy's actions and accusing the health secretary of putting people at risk by spreading misinformation, particularly about vaccines.