By 2003, the global HIV/AIDS situation was reaching its deadliest peak. The previous year, 4.8 million people contracted HIV and 2.75 million died, making it one of the worst years of the HIV epidemic.

It wasn't due to a lack of treatments. In the '90s, effective medications had been developed that made HIV a manageable condition rather than a death sentence. But these drugs were available almost exclusively in richer countries. So the burden of illness and death shifted to lower-resource countries.

People living with HIV in those countries, which were often the hardest-hit by the epidemic, had "no chance of accessing treatments at all," Dr. Wafaa El-Sadr, director of ICAP at Columbia University and professor of epidemiology and medicine at Columbia Mailman School of Public Health, told NPR. (The global health group ICAP was originally founded to address the HIV/AIDS epidemic.) "There was really absolutely no hope."

Then, in his January 2003 State of the Union address, President George W. Bush made an announcement: The United States would undertake a massive investment to combat HIV/AIDS around the world.

Those working in the field remember watching the speech and wondering if this could be a much-needed turning point.

"There needed to be something major, something big, something unprecedented, to be able to tackle this level of despair, this level of hopelessness," El-Sadr said. "It was kind of a remarkable moment. I was thinking, 'Oh, my. This might be it.'"

That was two decades ago. The U.S. President's Emergency Plan for AIDS Relief, or PEPFAR, soon become a greater triumph than experts like El-Sadr had dared imagine. It's the largest health commitment ever made by any country, now totaling more than $100 billion in more than 50 countries. And its work continues.

"It's been an amazing program," said Kellie Moss, an associate director for global health and HIV policy at the Kaiser Family Foundation. "It's been incredibly, wildly successful beyond anyone's expectations."

The U.S. commitment spurred lasting contributions from other countries as well.

"I remember hearing the announcement and was just gobsmacked that a country like the U.S. was going to make that kind of commitment," said Dr. Sharon Lewin, director of the Doherty Institute for Infection and Immunity at the University of Melbourne and president of the International AIDS Society. "PEPFAR has been like the most amazing thing in the history of HIV, I'll be honest, and transformational in what it was able to deliver."

Bush returned to Washington on Friday to extol PEPFAR's progress and to urge continued support when Congress takes up reauthorization of the program this year.

"I don't really come to Washington often," he said. "But I'm here to remind people that American taxpayers' money is making a huge difference, a measurable difference in saving lives: 25 million people. This program needs to be funded. For the skeptics, all I ask is, look at the results. If the results don't impress you, nothing will impress you. "

Yet challenges still remain, and the clock is ticking on the United Nations' goal to end the epidemic by 2030, which PEPFAR has also adopted.

In 2021, 1.5 million people were infected by HIV and more than 650,000 died from HIV/AIDS. More than 38 million people live with HIV around the world.

"I think people forget, and they feel sometimes that HIV has been taken care of," El-Sadr said. "But that's not the case."

Partnerships are a key to success

The program, which is headquartered at the U.S. State Department, supports countries that have been hit hard by HIV.

"We are just a partner — a trusted partner," Ambassador John Nkengasong, the U.S. global AIDS coordinator and special representative for global health diplomacy, told NPR. Nkengasong, who is Cameroonian-American, is the first Africa-born leader of PEPFAR.

PEPFAR provides support for buying and giving out treatments, training and employing health workers, building and maintaining laboratories and monitoring where the virus circulates and how it evolves.

Partnerships — with national and local officials as well as nongovernmental organizations — have been key to PEPFAR's success, experts say.

PEPFAR improved perceptions of the U.S. in other countries and also forestalled a security crisis, because illness and deaths were "threatening the stability of nations," Moss said.

HIV was "a serious security threat, a serious economic threat and a serious health threat," Nkengasong said. But there have been unintended benefits to addressing these risks. Countries receiving assistance have seen a 2.1% rise in GDP as well as a significant rise in childhood immunizations and a 35% drop in all child mortality.

Countries need to continue ramping up testing, treatment and prevention, Lewin said. About 75% of people who have HIV are on treatment. That means a quarter of them do not receive treatments to save their lives and reduce transmission by bringing levels of the virus down so low that it's not passed on.

Certain groups still don't benefit from HIV programs as much as they could — including children and young people, men who have sex with men, sex workers, people who inject drugs and other vulnerable populations like prisoners and migrants, said El-Sadr. That's because it can be hard to identify those who are HIV-positive and ensure steady access to treatment, and stigma still prevents many from receiving care.

And because HIV is a lifelong disease, "the pool of people needing treatments is just growing," Lewin said.

More research needs to be done on innovations, Nkengasong said, such as injectable treatments that, unlike pills, last for months — and more.

"Why not aspire to have a vaccine and also a cure in the next couple of years? So that we can truly, by the year 2030, bring HIV/AIDS to a true end."

A model for other health challenges

President Biden, in his 2023 State of the Union address, marked the program's 20^th anniversary with two brief sentences, hailing the "huge success" of the bipartisan program. Then, he said, "I believe we can do the same with cancer."

In fact, the gains made by PEPFAR have strengthened the world's ability to respond to other conditions and outbreaks, experts said — including COVID-19, Ebola, Marburg, and mpox.

"The overall goal is to strengthen a health system to be flexible and adaptable to whatever it faces, whether that's an infectious disease or a major chronic health problem," Moss said. "Anytime there's something that is new, it will stress the health system, but the hope is that we're building back systems that are more resilient over time."

The investments made in health have enabled a trained force of health workers to pivot to outbreak response and HIV labs to add testing and genomic sequencing to discover how the viruses are evolving.

"The benefits were seen beyond HIV, because you had an infrastructure or capability in managing infectious diseases," Lewin said. And when other outbreaks strike, progress on HIV can continue in spite of upheaval. In 2020, despite COVID-19, countries receiving PEPFAR support were still able to make gains in treating HIV and lowering patients' viral loads, according to a study from the U.S. Centers for Disease Control and Prevention. "Countries which had the PEPFAR programs did better in COVID, which I think is just absolutely extraordinary," Lewin said.

PEPFAR should continue focusing on HIV since the virus still has a huge effect on global health, El-Sadr said — but the investments in PEPFAR can give countries a leg up on other challenges. The same tools that help fight HIV — health workers, labs and more — can also be used to respond to other crises, whether they are non-communicable diseases, the next pandemic, antimicrobial resistance or any other health threat that emerges.

During Uganda's recent Ebola outbreak, Nkengasong advised officials to use the health-care workers, clinics and labs supported by PEPFAR to respond to the hemorrhagic fever. It's a good idea for health workers who are normally focused on HIV to respond quickly to other outbreaks, like cholera, Ebola, and mpox, so that there are as few disruptions as possible to HIV care, he said. "Until and unless you get rid of those [other health concerns], there's no way that we get back to the business of fighting HIV/AIDS."

Suppressing other outbreaks quickly means that resources are less likely to be diverted from pressing challenges like HIV in the long run. And by addressing existing health issues now, countries will be in a stronger position to face whatever other crises arise, Nkengasong said.

"The best way to prepare for the unknown is to adequately resource the known," he said. "You are preparing yourself for the future."

Bipartisan support 2 decades on

PEPFAR is up for its fourth authorization from Congress this year. It is expected to move forward, since the program has long been seen as a bipartisan success story.

"It enjoyed strong bipartisan support historically and that hasn't changed — despite changes in administration, despite changes in Congress, it's still received robust support on the Hill," Moss said.

On a visit to South Africa on Thursday, five U.S. senators vowed to renew PEPFAR, with Sen. Lindsey Graham calling it "the right thing to do" at a press conference.

Every five years, Congress signals its priorities when reauthorizing PEPFAR — for example, asking the program to focus on children orphaned and made vulnerable by HIV/AIDS or providing nutritious food to those affected by HIV.

Some of those initiatives have been misses. The U.S. spent $1.4 billion promoting abstinence to prevent HIV, which proved to be a failure. Critics said that program was an attempt to force certain values on other nations – legislation meant to appease conservative lawmakers that was later phased out.

"Is there room for improvement? Yes, we continue to learn lessons," Nkengasong said of missteps.

Yet, he said, "PEPFAR is, in my view, the greatest act of solidarity that humanity has ever created in solving an infectious disease challenge like HIV/AIDS."

During their visit to South Africa last week, the five U.S. senators met with a young woman who was diagnosed with HIV — and went on treatment — years ago, Nkengasong said. She's now married, with two young daughters who are HIV-negative. Stories like hers show the importance of reauthorizing PEPFAR, he said.

"We have millions of people who are in treatment now, and if we take our foot off the pedal, then we will begin to see the virus reappear" among those in treatment — and spread to others, Nkengasong said.

The crisis is not over, El-Sadr said. "We've come a long way, but I think the work is not done," she said. "We have to continue with the same vigor, with the same momentum, with the same energy to be able to get to the point where we want to get to — which is really to end this epidemic."

Melody Schreiber (@m_scribe) is a journalist and the editor of What We Didn't Expect: Personal Stories About Premature Birth.