Treatment is prevention

Erika Check Hayden

This week, political leaders meet in New York for a United Nations summit that will frame the ongoing fight against HIV/AIDS. The conference comes a decade after the UN meeting at which heads of state committed the first major funding to the battle; as a result, 6.6 million people are now receiving antiretroviral drug therapy to keep their HIV infection under control — 22 times the number in 2001, according to estimates by the Joint UN Programme on HIV/AIDS (UNAIDS).

But 9 million people who need treatment are still not getting it, and global economic woes threaten to weaken international AIDS programmes. Anthony Fauci, head of the US National Institute of Allergy and Infectious Diseases, explains what scientists hope the UN meeting will achieve.

How is the research landscape different going into this meeting than it was a decade ago?

A considerable number of people have been put on therapy. But for every person who goes on therapy, two or two-and-a-half people get newly infected, so there's been this question of the balance between treatment and prevention.

A real game changer occurred just a few weeks ago with the clear demonstration in heterosexual couples that when you start treatment earlier rather than later, you not only benefit the person infected, but that person is also 96% less likely to transmit the virus to their uninfected partner than if they were not treated (see 'HIV treatment shown to prevent spread of virus'). So people can say with a good deal more confidence that treatment is prevention.

What does that imply for global AIDS policy?

We have now so many types of prevention in our armamentarium, including treatment. So rather than have the tension between treatment and prevention, as there was previously, let's try to seek out, test, and treat as many people as we possibly can, because when you treat people, you are doing prevention. So that brings up the big question — which is that it's going to require a lot of resources.

How do you frame that question?

The fundamental policy decision is: is it better to make investments now, even with the restricted resources we have available, and slow down or even get control of the pandemic, rather than not making the investment now, and only having to pay down the line, and possibly paying more.

The UN wants countries to commit to treating 13 million people by 2015 at a cost of $22 billion, but this would not even treat all the people who will need it by that time. Is this where we should aim, given what we know about treatment as prevention?

 It's a reasonable goal. The issue at hand — the big elephant in the room — is are the parties responsible able to come up with the resources to make this happen? We have a confluence of enormous opportunity to turn around the global pandemic at the same time that we have an almost unprecedented constraint on resources. This is going to be the subject of some serious discussion in New York. Despite the constraints on resources, we have a real opportunity not only to save a lot of lives, but in the long run, to save money.

Many researchers are now saying that we have the tools needed for effective prevention, and social phenomena are the main obstacle to slowing the spread of HIV (see Comment: 'Stigma impedes AIDS prevention'). What more can researchers do to solve this problem?

It isn't as if we're going to be able to access every individual immediately, but there are programmes that can be enhanced that will allow us to penetrate into those areas of society that have been difficult to reach. Can we do this tomorrow? No, but we don't have to. We can start doing it over the next couple of years and we'll get better and better at it.

What are researchers looking for out of the meeting?

What I'm going to do in New York is put the data on the table. There's no more doubt that treatment can serve as prevention. My purpose is to say to policy makers: here are the data; you have to make up your mind about whether you want to implement the programmes that have been proved to work — to make it almost scientifically obvious to them what they need to do. Nature.com