In a memo obtained by NPR, acting Health Secretary Dorothy Fink forbade staff from public communications on most matters until Feb. 1, unless they get express approval from "a presidential appointee."

President Trump has imposed temporary freezes at the National Institutes of Health on meetings, travel, communications and hiring, citing the need to review protocols.

The U.S. Department of Health and Human Services has paused public communications until Feb. 1 as Trump appointees take control of health agencies.

The Trump administration’s freeze on some government work and communications on health topics pending a political review is alarming the nation’s scientists, who say the move could delay essential information and slow funding for potentially life-saving initiatives.

Scientific meetings were canceled, and research data on the bird flu outbreak was delayed, amid confusion over the directive.