XVII International AIDS Conference Mexico City Notebook: Day Three
An Interview With Science Magazine Correspondent Jon Cohen
August 5, 2008
Jackie Judd: Jon Cohen, welcome back.
Jon Cohen: Thanks Jackie. Glad to be back.
Jackie Judd: Second full day of the conference and today, it was all about prevention.
Jon Cohen: Prevention day yes. Well it was a very powerful opening session this meeting with a talk by Mike Cohen from the University of North Carolina where he mapped out all the different places you can act to intervene against HIV, before someone is infected, the first few weeks after they are infected, the first few months after they are infected, long-term when they are infected. There are different strategies to prevent HIV from getting the upper hand in each of those cases. He did a, I think, what many people here thought was a tremendous job outlining all of the possibilities.
The bottom line is that everyone now recognizes that the idea that one single thing, one magic bullet is going to lead to the prevention of HIV spread is as silly as the idea that one drug is going to stop HIV, which was initially the hope with drug treatment. It is now the era of cocktail prevention, of highly active combination prevention. I think it is high time.
Jackie Judd: Because we know what the treatment is, it is a question of the delivery system but prevention still more of a puzzle?
Jon Cohen: Well we know that no single preventive idea solves the problem. There is no vaccine that, before there was a polio vaccine, there was no hope. A polio vaccine showed up. Polio went away in the United States between 1955 and 1961 with a vaccine. It disappeared. Well there is no vaccine here. So we have got to come up with other strategies that mix and match all these different things that maybe work a little bit.
Jackie Judd: You said, before we started taping, that one of the things that struck you about the presentation Mike Cohen made was that his optimism.
Jon Cohen: Yes. He was extremely optimistic about a biomedical approach to prevention. He put up a slide that showed all the trials of biomedical approaches and how many have failed. We are talking about close to three-dozen studies that have failed. Vaccines, microbicides, treating sexually transmitted infections, all these different ideas have failed but he is extremely hopeful about something that is being studied today that has yet to prove itself and it is called pre-exposure prophylaxis.
It is being studied in thousands of people around the world. He put up a slide that showed all of the countries and cities that are now studying this. The idea is that an uninfected person will take an anti-HIV drug before having sex and that that will protect them much in the way when you go to a country that has malaria, you might take a malarial pill to prevent getting malaria. Has it proven itself? No. Have most things in this arena failed? Yes.
So why is he so optimistic that he would stand in front of thousands of people and say I am fairly certain this one is going to work? The reason is because there is good evidence already that it does work in prevention of mother-to-child transmission. When a baby is born to an infected woman, both the mother and the baby ideally receive a dose of anti-HIV drug to prevent the transmission. It works powerfully.
There are also monkey studies that show this strategy with the right drugs or combinations of drugs is very powerful in monkeys. The data from the monkey studies do not look anything like vaccine studies. If you saw a vaccine monkey study that worked this well, believe you me, people would be dancing in the streets.
Jackie Judd: Put this in a little bit of context. Tell us why it is so important when somebody like Mike Cohen says what he said today.
Jon Cohen: I think people are feeling a sense of hopelessness about biomedical interventions in part. There is also abundant evidence that behavioral interventions by themselves are just getting people, telling people to use condoms have a limited power.
Circumcision is one of the biomedical interventions that have worked. In fact, there are four trials that have worked in medical interventions. Three of them are circumcision studies. Well circumcision only prevents infection 60 percent of the time. So even that is not that powerful. Yes, it has power and that is great but it is not the answer to the problem.
So I think when somebody stands up and says hey we have got a lot of trials under way right now and a few of these look really promising. It is kind of cutting against the grain and saying there is reason for optimism.
Jackie Judd: And so when you talk about, when prevention is talked about here, is it almost exclusively in the biomedical arena? Is there still a focus on behavior change?
Jon Cohen: Absolutely. It is underused or misapplied in many, many places. There was a lot of criticism today about abstinence only or even the notion of ABC of abstinence, behavior change, and condoms. There was one session I went to where one of the presenters asked everyone in the room to raise their hand if they wanted ABC to be put in the trash bin and die today.
All of it is just oversimplifying things rather than accepting the complexity of it. So yes, behavior changes are seeing a lot of attention but a big problem with behavior change is it is much harder to measure your impact than it is when you do a biomedical study. If I give you a drug, I can say it worked, it did not work. I test you before and after but if I do behavior changes, there are all these other forces at play. It is just dirtier. It is a messier science.
Jackie Judd: The other thing I wanted to talk to you today about was what you called the know your epidemic discussions. Where is that coming from?
Jon Cohen: There was a chart put up today of what is driving the epidemic in each region of the world, so Africa, Asia, North America, and what you see is that peoples behaviors that drive the epidemic differ from region to region. So in some areas, a third or half the epidemic is driven by men who have sex with men. Maybe a third is injecting drug users and a portion of it is mothers transmitting to children.
In other areas, there is really no injecting drug use to speak of. It is mainly heterosexual sex. There is very little detected men who have sex with men. The idea is, you see, you cannot do a one size fits all prevention program. You need to tailor your response to your epidemic and in far too many places, they do not want to accept some of the main drivers of their epidemics. Many countries for
Jackie Judd: So is it know your epidemic or admit your epidemic?
Jon Cohen: It is both. There are places that do not know their epidemic simply because they are not really addressing their problem. There are other places that do not want to see it. Injecting drug users are reviled by many governments.
They do not want to see that they have injecting drug users and indeed they have criminal sanctions against injecting drug users. The same is true with men who have sex with men. Many, many countries have laws that actually penalize men for having sex with men.
In addition to there being laws, there are countries that torture men who have sex with men. They do not want to see it. If you do not want to see it, you are not going to find it.
Jackie Judd: And you cannot prevent this?
Jon Cohen: And you cannot prevent it. What are you going to do about something that does not exist because you were not looking for it? My sense of all this, Jackie, is that in one realm, there are so many things we know that work that are not being applied for prevention.
I was describing it today to somebody. I said you know, it is as though I have got a bottle opener here and you have got a screwdriver and you are using the screwdriver to take a bottle cap off and I go but I have got a bottle cap opener. This thing just pops the thing off. You go, [makes noise], I have got a screwdriver. That, to me, is what much of the world is doing is they are just ignoring the fact that there are bottle openers.
Jackie Judd: I did not expect to end on that point but there you are. Thanks very much Jon Cohen and I will talk to you tomorrow.
This article was provided by kaisernetwork.org.