Last month, The New York Times and others published–in violation of a media embargo–world-shaking headlines of a “cure” for HIV. It’s huge news. 37 million people live with HIV and the extraordinarily resilient and adaptable virus has for decades kept a step ahead of cure researches. But the news was as confusing as it was explosive. First, because headlines claiming “cure!” quickly shrunk away into fourth-paragraph disclaimers about scalability and, second, because the word “cure” seemed to swap interchangeably with the more conservative word “remission.”
Here’s what happened: two people who once had HIV underwent aggressive cancer treatment and then stopped their HIV medicine for long periods of time during which highly-sensitive HIV tests haven’t detected the virus. Timothy Brown, aka the Berlin Patient, once had HIV but, as far as we can tell, has been living without it for 12 years now. The London Patient, who has remained anonymous, hasn’t had HIV for about 18 months, according to an announcement at the Conference on Retroviruses and Opportunistic Infections at the beginning of March 2019 and an article published around the same time in the journal Nature.
As part of their cancer treatment, both men received bone marrow transplants from donors with a special genetic mutation called “CCR5-delta 32.” The mutation makes it hard for HIV to spread into certain blood cells. Both men went off their HIV medicine and the HIV hasn’t rebounded. When the Berlin Patient news broke 12 years ago, it sparked a rush of efforts to recreate the results, but the HIV eventually rebounded in every case, until, it seems, the London Patient.
HIV is a great hider, treatment drives it into nooks and crannies of the body where, tucked away at such low levels, even our most sensitive tests can’t find it. But if treatment stops, HIV normally pops out and begins to spread again. This is why some people avoid the word “cure” and instead say “remission,” meaning we can’t find the virus right now, but it may show up again later. After all, there is no official consensus as to how long remission should last before it should be called a cure and there have been plenty of people we hoped were cured but turned out to instead be in remission.
This discussion is significant beyond the scientific technicalities; headlines about an HIV “cure” have extremely dangerous potential. The history of HIV has often been ugly—hundreds of thousands of AIDS deaths are more properly attributed to misinformation than the virus. Those deaths are tragic and inexcusable. The history of HIV is also, however, beautiful and inspiring: great movements fought inertia, ignorance and indifference with education, organizing, and now-famous campaigns that wedded science, law, and political pressure. HIV is a political and social issue as much as it is a biomedical one—and we already have tools to stop HIV from spreading and keep people living with HIV healthy if only we do the political and social work to ensure everyone can access them. While we want and need an HIV cure, we must be cautious that dreams of a cure in the future don’t cause complacency for the life-saving action needed now.
All that said, supposing we use the term “cure”, this is where we are: two people have been cured of HIV, but we (the rest of the world) do not have a cure for HIV. This is not a treatment many people can or should get—bone marrow transplants are expensive, traumatic, and chancy; risking, for example, new cancers, graft-versus-host disease, organ damage, and death. There is a reason we only give bone marrow transplants to people with serious cancer and not to everyone with HIV. And, in any event, modern HIV treatment is designed to reduce HIV to an undetectable level anyway, at which point the person has a basically normal life expectancy and quality and cannot pass the virus to their partners or children. In this sense, the only practical difference for Timothy Brown and a person who takes HIV medicine is that the latter has to swallow a pill every day whereas the former underwent a procedure that almost killed him. It is far preferable to live with treated HIV than undergo a bone marrow transplant, unless, of course, you need one for some other reason.
The development nonetheless holds exciting and fascinating significance beyond the Berlin and London Patients. For starters, the Berlin Patient’s cancer treatment was so brutal he almost died. The London Patient had a much easier time and achieved similar results, giving hope that things will continue to get easier. More importantly, the development pushes us into new understanding of HIV immunology and gives hope that gene therapy and editing might lead to a true cure in the foreseeable, though not immediate, future.
This hope should spur us up and onward. In the meantime, we have treatment that keeps people healthy and stops the spread of HIV. Yet nearly half of the 37 million people who need treatment don’t have access to it, and so, while we must work toward a cure, we cannot wait for one.