HIV Cures: Where We Are, Realistically
An infectious-diseases specialist breaks down the reported breakthroughs
Newswires remain abuzz around two reports of "functional" HIV cures. The first, of a Mississippi baby treated with potent cocktail of anti-HIV drugs within 31 hours of HIV diagnosis, was touted as "proof of principle that we can cure HIV infection" by Dr. Deborah Persaud of Johns Hopkins Children's Center. Then, last Friday, French investigators reported "functional cure" of 14 patients with HIV treated early with potent medications.
What does "functional cure" mean? Should the Nobel Committee be dusting off medals?
One of my clinic patients recently asked if he could stop his medicines. "Is a cure finally here?" Unfortunately, the answer is a resounding "Not yet."
Every year, over 2.5 million people join the 34 million who are already infected with HIV. Still only a fraction have access anti-HIV drugs. An HIV vaccine is years off.
It would be a huge deal if we could celebrate a true cure for HIV. But these patients we've heard about are highly unusual. All were treated very early with powerful anti-HIV regimens that most patients with HIV do not start until years after infection. Even when we diagnose HIV early -- itself a difficult task -- many HIV-positive patients do not begin treatment for years after infection. That is in part because of the great cost of HIV treatment.
Even if we could surmount the massive economic and logistical obstacles to widespread early HIV treatment, the same French investigators estimate that only 15% of patients treated early are likely to see the same benign-appearing clinical course that they reported.
These cure reports are also very early. The Mississippi baby was observed for 26 months, and the 14 HIV-infected patients in France were followed for 48-115 months. Since the average untreated HIV patient develops AIDS within 120 months, these studies are interesting but can't really confirm permanent protection from AIDS. Might the virus come surging back after a short-lived hiatus? It's possible.
We already know that some people exhibit partial protection from HIV infection. Several years ago epidemiologists identified a small group of commercial sex workers in Nairobi who were highly exposed to HIV but didn't acquire HIV infection. Plus, there is the quixotic story of a suicidal young man who injected himself with HIV-tainted blood but who didn't get infected. More commonly, most HIV doctors see rare patients who do well for years without ever being treated for HIV therapy. Called long-term nonprogressors, these patients avoid immune system damage from HIV for years off of therapy, likely due to some combination of potent immune control of HIV and (less commonly) a dysfunctional HIV virus. So, while the reports of Persaud and her French colleagues are important contributions to the field, it's difficult to know particularly if these patients are something new entirely at all.
Lastly, and importantly, only one of the reported patients was actually cured in the common sense of the word. No HIV is detectable in the Mississippi baby after longer than two years. But all 14 French patients reported have low levels of detectable HIV after treatment was stopped, suggesting that for them HIV is more accurately "under control" or "not doing bad things right now."
That's a far cry from cured.
This is an essential, important distinction. For years HIV prevention experts have been working hard to improve upon the lackluster success of the A-B-C campaign for HIV prevention: Abstinence, Being faithful, and Condom. These methods definitely slow the spread of HIV, but decades into the epidemic they have failed to prevent millions of new people from becoming infected. While recent research in preventive HIV treatment and preventive topical creams has been promising, it would be foolhardy to offer false reassurance at this early juncture. We need people to keep on using condoms, to stay on treatment, and to wait for more universally applicable approaches to prevention.
When my HIV patients ask if it's time to stop their medications, I tell them to keep their champagne corked and stay the course. When my high-risk patients ask if they can stop using condoms, I remind them about the ABC's, and I give them condoms.