What the New HIV Breakthroughs Mean for the Future of the Disease

There was exciting news this week in the battle against HIV/AIDS, much of it coming out of the annual Conference on Retroviruses and Opportunistic Infections (CROI), which took place in Boston. But perhaps the biggest story was that, for the second time in history, a baby born with HIV has been declared free of the virus after early, aggressive treatment.

While “baby cured of HIV” is, for sure, a thrilling headline, scientists are more cautiously hopeful than some media outlets would suggest. “That case is definitely intriguing,” Reilly O’Neal, editor of the San Francisco AIDS Foundation’s blog BETA, who attended the conference, tells Yahoo Shine. “The baby was tested with incredibly sensitive tests. The case supports the idea that very early treatment has the potential to dramatically reduce HIV reservoirs [the genetic code of the virus that 'hides' in the body], which are a major obstacle in curing HIV.”

More on Yahoo: Doctors Hope for Cure in a 2nd Baby Born with HIV

The now-famous "second baby" was treated in Los Angeles after being born last year to an HIV-positive mother who had received no prenatal care. (Treating pregnant mothers reduces the transmission of the virus to their babies.) Only four hours after the baby was born, doctors began administering an antiretroviral cocktail, the same one that had successfully led to remission in an HIV-infected newborn in Mississippi three years ago. Now, nine months later, there is no detectable trace of the virus in the second baby’s cells and she continues to undergo treatment.

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So does that mean we've now found a cure for HIV? Well, not yet. On Wednesday, one of the baby's physicians, Yvonne Bryson, an infectious disease specialist at Mattel Children's Hospital UCLA, told the audience at CROI, "We don't know if the baby is in remission, but it looks like that." According to O’Neal, Dr. Deborah Persaud of Johns Hopkins University, who tested the baby and also spoke at CROI, was careful not to refer to the infant as “cured.”

Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases (NIAID), explains to Yahoo Shine, “The only real proof is if you stop therapy and the virus doesn’t bounce back.”

That search for proof, of course, begs the question: When is it ethical to withdraw treatment to test for remission? Five months after the mother of the Mississippi baby ceased giving the girl her medications at 18 months old, her doctors were shocked when a blood test revealed that she was still HIV-free. Fauci says that both of these cases suggest the promise of early intervention in the prevention of HIV transmission to newborns. (Right now, about 200 babies are born with HIV in the United States annually.)  In April, NIAID will be funding a series of trials in which babies will be treated for the virus and carefully withdrawn from treatment under highly controlled conditions.

And there's more good news: A limited but hopeful pilot study presented at CROI and published in the New England Journal of Medicine on Wednesday focused on gene editing — the process of removing genetic material from a person, altering it to make cells become HIV-resistant, and replacing it in the body. Genetic modification has the potential to both prevent and reverse HIV. The goal of the study was to test the safety of the technique.

A small percentage of people are actually resistant to HIV because their immune cells lack CCR5, a protein that acts as a gateway to the virus. In 2008, a man named Timothy Brown, known as the “Berlin Patient,” was cleared of HIV after receiving a bone marrow transplant for leukemia from a donor who happened to have the CCR5 mutation. In the current study, which built on that case, researchers removed blood from 12 HIV-positive men to disable CCR5 in their immune cells. The cells were returned to their bloodstreams through a transfusion. Researchers found that the modified cells did increase in vivo, and when patients went off their medication as part of the study, the modified immune cells remained more resistant to HIV than regular cells. “It was an important conceptual advance, but not the end of the game,” says Fauci.

Rowena Johnston, PhD, the vice president and director of research at amfAR, says she’s optimistic about the future of gene therapy. “Some people think it's pie in the sky, especially for poorer countries with fewer resources,” she tells Yahoo Shine. “But if you had a potential to cure 34 million people, someone’s going to figure out a way to do it.”

Another compelling line of research that was published this week involved two related studies that looked at the efficacy of long-term antiviral injections in monkeys. In one study, by the CDC, six monkeys were given a monthly injection of an experimental antiretroviral drug, and six were given a placebo. All were exposed to HIV twice a week. After four exposures, the six monkeys on a placebo tested HIV-positive, but after 20 weeks, the other six remained virus-free. The second study, by the Aaron Diamond AIDS Research Center at Rockefeller University, had similar results. Previous research has shown that taking a daily antiretroviral pill has a strong protective effect, but some researchers believe that a monthly or quarterly injection might be more practical and an easier regimen for some people to stick with.

And finally, one more intriguing study presented at CROI was the PARTNER study. “Some of the most exciting news this week comes from this study,” O’Neal says. Researchers analyzed data from more than 750 mixed HIV-status couples who were having sex without condoms. It found that no cases of HIV transmission took place when the positive partner was adhering to effective antiretroviral therapy. “The real-world implications are huge,” she shares. “Researchers could not rule out that HIV infections might happen over the long term … but people in mixed-HIV status couples can use these data to make their own informed decisions.” The final results of the PARTNER study will be published in 2017.

While we may still be years away from a cure for HIV, from treatment to prevention, we’ve come a long way from the dark days when a diagnosis was a death sentence.  And that's good news now.