Several US Centers for Disease Control and Prevention websites and datasets related to HIV, LGBTQ people, youth health behaviors and more have been removed after the agency was directed to comply with executive orders from President Donald Trump.

CDC data’s “explicit purpose” is to guide researchers toward the places and people who most need attention, Patrick Sullivan, an epidemiologist at Emory University and a former CDC Epidemic Intelligence Service officer, told me. As the changes unfold before him, he said, “it’s hard to understand how this benefits health.”