Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, has spent the past 40 years of his career fighting the AIDS epidemic, but he can still remember one of the first times he encountered data about the disease, in June 1981.
"It was a particularly transforming time," he told TODAY's Joe Fryer in a segment aired on Wednesday for Pride Month. "I can remember very distinctly sitting in my office outside my lab in the clinical center hospital where I saw the first (report) describing the first five patients from Los Angeles with this curious new disease, with nobody knowing what was going on."
The patients were all "otherwise previously healthy gay men," Fauci said, which he found "rather curious," until the following month, when another report on 26 patients came out, indicating that young, gay men in San Francisco and New York City were also showing signs of the disease.
"I remember sitting at my desk looking at that and literally getting chills up and down my spine saying, 'Oh my God, this is a new disease. It has to be a new disease,'" he recalled. "I had no idea what it was or where it came from."
"Everything was great, my career was going along well, and I said, 'Wow, I've got to study this new disease because it looks like it's an infection, and it looks like it's destroying the immune system.' So I made a decision right then that I would start and literally stop what I was doing."
He went to work for the National Institutes of Health as a senior investigator. Some of his mentors questioned the decision, he added, because "nobody had any idea whether it was going to all disappear in a month or so ... but that was the beginning of a journey that I've been on for the last 40 years now."
In 1984, Fauci assumed his current role as the director of the National Institute of Allergy and Infectious Diseases, as the AIDS crisis was capturing national attention. He faced criticism from AIDS activists in the early years who believed he was ignoring the outbreak. At the time, Ronald Reagan was president, and through much of his first term, he did not acknowledge the virus's existence.
Prominent gay activist Larry Kramer, who died in May last year, also accused Fauci of being too inexperienced to hold his position, though Kramer and the doctor eventually developed a friendship through their work to fight the disease.
Fauci told Fryer that Reagan's stance on the AIDS epidemic was a challenge and that it "prompted me to be very forward and proactive in not only my own research but actually out there in the public speaking about it ... trying to get people's attention to it."
"I never really had any aspirations to be the director of the institute, but it was clear to me that we were not paying as much attention to infectious diseases in general, but specifically to HIV," he added.
In the early days, securing resources for the fight against AIDS was difficult.
"We were trying to convince people that this was not something that was going to go away, this was something that was gonna get worse and worse," Fauci said.
The major funding started during George H.W. Bush's presidency.
"I was fortunate enough to get to know him personally and become actually pretty friendly with him when he was vice president," Fauci recalled. "He promised me that if he became president, he would really take a really close look at what we're doing and see if we can improve it. ... He kept his word when he became president."
Since then, there have been several major milestones with preventing the spread of HIV, namely antiretroviral therapy, which can reduce the viral load of a person infected with HIV to the point that the individual won't spread it, and drugs like PrEP, which can protect a non-infected individual from contracting the virus.
Fauci explained that the disease has gone from "almost an absolutely inevitable death sentence to people who are now living virtually normal lives."
Antiretrovirals in particular, which led to the messaging, "Undetectable equals untransmissible," were "totally transforming," Fauci said.
"It was important for the people who were living with HIV to know that, scientifically, they did not pose a threat to anyone if, in fact, they took their medicines and their viral load remained low detectable," he said.
"It helped to take some of the stigma away from persons living with HIV," he added.
Fauci called PrEP, which stands for pre-exposure prophylaxis, "an extraordinary success." The first drug of this kind for HIV, a pill called Truvada, was approved in 2012. Earlier this year, the Food and Drug Administration approved the first monthly shots, replacing daily pills, to help patients maintain their treatments more easily and with more privacy.
But the absence of an HIV vaccine still looms large in the fight against the disease. Fauci said that one isn't available "was not for lack of trying" and that he doesn't know when it might be. One major reason, he said, is that the the body doesn't naturally produce an adequate immune response to the virus.
"We have highly effective vaccines against COVID-19 because we know the body can do it, and we induce the body to do it," he explained. "With HIV, that's not the case. We've got to do better than what natural infection does."
"Hopefully some of the things we've learned from the ... COVID-19 vaccines will ultimately help us to develop a successful and highly effective HIV vaccine. So we're still hoping that that's going to come to pass."