Sept 3 (Reuters) -

Pfizer ( PFE ) and Moderna ( MRNA ) on Wednesday defended

their COVID-19 vaccines as having saved millions of lives

worldwide, in separate responses to U.S. President Donald

Trump's demand that pharmaceutical companies should justify the

success of their pandemic drugs.

In a post on Truth Social, Trump asserted that he has seen

"extraordinary" data from companies such as Pfizer ( PFE ), but

criticized them for withholding results from the public and the

Centers for Disease Control and Prevention.

Pfizer ( PFE ) welcomed Trump's demand for openness and pointed to a

dedicated section on its website where clinical trial findings

and safety updates are posted. Moderna ( MRNA ) said it would compile

previously disclosed research and findings on its website.

"We are immensely proud of the role we played in the

historic achievements of Operation Warp Speed," Moderna ( MRNA ) said,

praising the U.S. government's 2020 initiative to accelerate

vaccine development, manufacturing and distribution.

Pfizer ( PFE ) CEO Albert Bourla called Operation Warp Speed a

"profound public health achievement" under Trump's leadership,

adding that the program helped in averting over $1 trillion in

healthcare costs.

The companies' announcements come amid escalating turmoil at

the CDC. Last week, director Susan Monarez was fired less than a

month into her tenure after resisting changes to vaccine policy

that were advanced by Health Secretary Robert F. Kennedy Jr, who

was handpicked by Trump earlier this year.

Her removal sparked the resignation of four senior CDC

officials, who blamed the erosion of public health credibility.

Kennedy has also rescinded federal COVID vaccine

recommendations for pregnant women and healthy children and

halted about $500 million in funding across 22 mRNA vaccine

research projects, including those targeting COVID.

As tensions over federal immunization policies and public

health directives grow, Florida on Wednesday announced plans to

end all state vaccine mandates, including for children to attend

schools.

Kennedy is set to testify before the Senate Finance

Committee later this week, where lawmakers are expected to probe

the CDC's leadership crisis and ongoing policy shifts.

Pfizer ( PFE ) also said new information on its latest vaccine

strain, recently cleared by the U.S. Food and Drug

Administration, will be published in the coming days.