During his first term, President Donald J. Trump unveiled a bold initiative to end the H.I.V. epidemic in the United States by 2030 by focusing on 57 jurisdictions with the most urgent needs.
The plan, which Mr. Trump announced in 2019 at a State of the Union address, surprised advocacy groups. But it was widely lauded, and successful.
By 2022, the plan had driven down new infections nationwide by 30 percent in adolescents and young adults, and by roughly 10 percent in most other groups.
This time around, the Trump administration’s stance on H.I.V. appears to be much the opposite.
The Department of Health and Human Services is now considering shutting down the H.I.V. prevention division of the Centers for Disease Control and Prevention and shifting some of its activities to a different agency, according to federal officials.
The C.D.C. provides funds to states and territories for detecting and responding to H.I.V. outbreaks, prevention, syringe exchange, expanded testing in emergency rooms and education and awareness. Roughly one in four new diagnoses of H.I.V. is made with agency funds.
The administration’s plan has not yet been finalized, and its potential timing is unclear.
“It’s not 100 percent going to happen, but 100 percent being discussed,” said a federal official who was not authorized to speak to the media about the matter.
H.I.V. prevention efforts, including clinical trials, in much of the world have already been halted with the gutting of the U.S. Agency for International Development.
And some federal funding for prevention and treatment was cut because the grants were related to transgender people, who are among those at highest risk of H.I.V.
In addition, the National Institutes of Health has terminated funding for dozens of related studies, including those on H.I.V. in children; the role of substance use; and increasing the use of preventive therapies among underserved groups, such as Black women.
The first Trump administration’s H.I.V. plan focused on helping many of these groups.
The initiative aimed to prevent infections in poor Black communities, and among gay and bisexual men and transgender women, some of the groups with the highest risk of contracting H.I.V.
“It was not his constituency,” Adm. Brett Giroir, who served as deputy secretary of health and human services in the first Trump administration, said in an interview last fall. But “the president was wildly supportive of that.”
The states where the initiative’s efforts were focused cut new infections overall by more than 20 percent by 2022. “That’s exactly what we were trying to do, and we did it,” Admiral Giroir said on Tuesday.
The first Trump administration also enforced government-held patents on preventive drugs to negotiate better deals from the manufacturers.
“These actions made a real difference,” said Jeremiah Johnson, executive director of the advocacy organization PrEP4All. But, he added, “it doesn’t seem like the current administration is motivated by prior accomplishments.”
The administration is considering a tentative plan to move some of the C.D.C.’s prevention programs to the Health Resources and Services Administration. That agency funds state and local health departments and community-based groups providing H.I.V. services, including through the signature Ryan White program.
“H.H.S. is following the administration’s guidance and taking a careful look at all divisions to see where there is overlap that could be streamlined to support the president’s broader efforts to restructure the federal government,” said Emily G. Hilliard, the department’s deputy press secretary.
No final decision has been made, she added.
Some organizations welcomed the possibility of moving prevention programs to H.R.S.A., which could provide comprehensive H.I.V. and maternal health services — so long as the C.D.C. continued to lead surveillance efforts and treatment guidelines.
“Providing new funding to H.R.S.A. opens up new possibilities for efficiencies in biomedical prevention of H.I.V. and other sexually transmitted infections,” said David C. Harvey, executive director of the National Coalition of STD Directors.
But other experts were deeply concerned about the potential loss of C.D.C. involvement.
“H.R.S.A. and their Ryan White program are terrific but focus on H.I.V. care and treatment,” said Mitchell Warren, executive director of AVAC, an advocacy group.
“They do not engage in H.I.V. prevention as a priority, which is why C.D.C.’s prevention focus is so critical.”
Michael Ruppal, executive director of the AIDS Institute, said officials at H.R.S.A. didn’t have expertise in how public health prevention was administered and measured.
“The leadership that’s within the C.D.C. and all the institutional knowledge there, we need it in the field — the states need it, the communities need it,” Mr. Ruppal said.
His organization helps Florida counties, including seven of the 57 high-risk jurisdictions included in the 2019 initiative, plan H.I.V. services. “It just seems like it’s counterproductive to his personality to let this happen to this program after he put his name on it,” he said, referring to Mr. Trump.
Some public health experts worried about the N.I.H. cutting grants for studies of stigma and prevention, particularly those involving some L.G.B.T.Q. populations. Most new H.I.V. infections are among gay and bisexual men, and transgender women.
“That’s where the epidemic is, and if you are not there, you are not addressing the epidemic,” said Dr. Chris Beyrer, director of the Duke Global Health Institute.
About 7 percent of the N.I.H. budget goes to H.I.V. research, but some Republican lawmakers have suggested that funding for H.I.V. should be commensurate with its national prevalence of less than 0.4 percent.
“That certainly would not be enough to continue the research toward a vaccine, which we need, and toward a cure,” said Dr. Beyrer, who serves as an adviser to the H.I.V. Vaccine Trials Network.
Given the changes to H.I.V. programs within the United States and abroad, public health organizations will need a new paradigm in order to continue their work.
That may involve companies negotiating purchase agreements directly with states and large nonprofits, or it may entail completely new models of partnership.
“We’ve got to snap out of any paralysis or any disbelief or shock, and we’ve really got to look at what needs to be built in the future,” Mr. Warren said.
“One of the biggest tragedies in all of this would be if we let this narrative be written entirely by people who don’t understand science or health care or research or foreign assistance,” he added.