Health experts are sounding the alarm after thousands of pages were removed from government websites, including critical health guidelines and resources. The purge, part of a recent executive order, is already creating risks for some of the most vulnerable communities.

Among the deleted pages are essential resources like vaccine information sheets, which doctors are required to share with patients before immunization. Also gone are detailed guidelines on safe contraception and data on how race and racism influence health outcomes. Even more alarming is the removal of a portal to a 20-year H.I.V. database, which doctors rely on to assess whether pregnant women in high-risk areas need testing.

While some of the information is still accessible elsewhere, the usual pathways to these resources are now broken. This has left healthcare providers scrambling and patients potentially in the dark.

“I’m deeply concerned and frustrated by what’s happening,” said one expert in infectious diseases, echoing the sentiment of many in the medical community.

The shake-up comes as part of a broader effort to eliminate references to terms like “transgender,” “L.G.B.T.,” and “pregnant person” from government materials. But many of the removed pages had no direct connection to these terms, leaving health professionals questioning the broader implications.

As the fallout continues, experts warn that these changes could have long-lasting effects on public health, particularly for those already facing barriers to care.