Heads of federal agencies turned Trump’s executive orders into mandates to cut communication with outside parties, halt most foreign aid, and pause legal filings.

U.S. health agencies including the CDC this week canceled meetings with external groups, paused some public health publications and told employees to freeze travel after directives from the Department of Health and Human Services,

The halt has frozen research grants, meetings and key health updates. “Everything is basically in chaos,” said one cancer researcher.