The director of the top public health agency in the United States has been fired after less than one month in the job, and several top agency leaders have resigned.

Centers for Disease Control and Prevention (CDC) director Susan Monarez isn't “aligned with” President Donald Trump's agenda and refused to resign, so the White House terminated her, spokesman Kush Desai said late on Wednesday.

The US Department of Health and Human Services had announced her departure in a brief social media post late on Wednesday afternoon. Her lawyers responded with a statement saying Monarez had neither resigned nor been told she was fired.

“When CDC director Susan Monarez refused to rubber-stamp unscientific, reckless directives and fire dedicated health experts, she chose protecting the public over serving a political agenda. For that, she has been targeted,” attorneys Mark Zaid and Abbe David Lowell wrote in a statement.

“This is not about one official. It is about the systematic dismantling of public health institutions, the silencing of experts and the dangerous politicisation of science. The attack on Dr Monarez is a warning to every American: our evidence-based systems are being undermined from within,” they said.

Her departure coincided with the resignations this week of at least four top CDC officials. The list includes Debra Houry, the agency's deputy director; Daniel Jernigan, head of the agency's National Center for Emerging and Zoonotic Infectious Diseases; Demetre Daskalakis, head of its National Center for Immunization and Respiratory Diseases; and Jennifer Layden, director of the Office of Public Health Data, Surveillance and Technology.

In an email, Houry lamented the crippling effects on the agency from planned budget cuts, reorganisation and firings. “I am committed to protecting the public's health, but the ongoing changes prevent me from continuing in my job as a leader of the agency,” she wrote.

She also noted the rise of misinformation about vaccines during the current Trump administration, and alluded to new limits on CDC communications.

“For the good of the nation and the world, the science at CDC should never be censored or subject to political pauses or interpretations,” she wrote.

Daskalakis worked closely with the Advisory Committee on Immunization Practices. Kennedy remade the committee by firing everyone and replacing them with a group that included several vaccine sceptics – one of whom was put in charge of a Covid-19 vaccines workgroup.

In his resignation letter, Daskalakis lamented that the changes put “people of dubious intent and more dubious scientific rigor in charge of recommending vaccine policy.”

He described Monarez as “hamstrung and sidelined by an authoritarian leader.” He added: “Their desire to please a political base will result in death and disability of vulnerable children and adults. I am unable to serve in an environment that treats CDC as a tool to generate policies and materials that do not reflect scientific reality.”

Some public health experts decried the loss of so many of CDC's scientific leaders.

“The CDC is being decapitated. This is an absolute disaster for public health,” said Public Citizen’s Robert Steinbrook. (AP)