Scientists Say A Gel Can Slow HIV Spread

Researchers meeting at the 18th international AIDS conference this week say a new vaginal gel can cut HIV transmission rates in half, if used properly. AIDS experts Anthony Fauci and Kevin Fenton join Ira Flatow to discuss the gel study, and other news from the conference.

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IRA FLATOW, host:

This is SCIENCE FRIDAY from NPR. I'm Ira Flatow.

Scientists and policymakers are packing up their posters and PowerPoint presentations and heading home from the International AIDS Conference in Vienna, Austria.

Today is the last day of the week-long meeting, which featured speeches from Bill Clinton and Bill Gates. Some good news was presented at the meeting. The number of people receiving drugs to treat HIV infections is up. And a promising development for controlling HIV transmission was talked about, a new gel that women can use that can help dramatically slow the spread of the virus.

Scientists also shared some new insight in how HIV infections get started and what happens in the body in just the minutes after exposure to the virus.

We're going to be talking all about that stuff this first part of the hour. Our number, 1-800-989-8255, interesting new developments in HIV and AIDS coming out of that meeting in Vienna.

Joining me now to talk more about it is Dr. Anthony Fauci. He is the recipient of the Presidential Medal of Freedom, director of National Institute of Allergy and Infectious Diseases. That, of course, is part of NIH. He joins us from Bethesda. Welcome back to SCIENCE FRIDAY, Dr. Fauci.

Dr. ANTHONY FAUCI (Director, National Institute of Allergy and Infectious Diseases, National Institutes of Health): Thank you, Ira, it's good to be with you.

FLATOW: You're welcome. Dr. Kevin Fenton is the director of the National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention. That's at the Centers for Disease Control and Prevention. He joins us from Vienna, Austria. Thanks for talking with us today, Dr. Fenton.

Dr. KEVIN FENTON (Director, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Centers for Disease Control and Prevention): Great, thanks for having me.

FLATOW: You're welcome. Before we get to the gel, Dr. Fauci, let's talk about the other news from the meeting, that some really remarkable new science coming out, what happens in the very first few moments that HIV is introduced. It's not really an easy infection to get, is it?

Dr. FAUCI: No, it's not. In fact, I had the opportunity to speak to the conference on that subject and in my lecture. And really, the bottom line of it all, Ira, is that the events that take place literally within minutes to hours of exposure, for example in sexual exposure when an infected semen gets into the vaginal vault, it really is a point of vulnerability for the virus because it is not easy for that virus to find the vulnerable cell that it needs to get the infection started.

And once it does, it goes through an amplification event of infecting other cells more and more and more. And then once it starts to spread widespread, then really in many respects, there's no turning back. So if we're going to be doing things like prevention from a variety of modalities, be it vaccine or pre-exposure prophylaxis or circumcision or what have you, it's very important to understand those early events, which we refer to as a very short and small window of vulnerability for the virus but a sure window of opportunity for us for intervention.

So it was really the scientific basis of how the infection gets started and what we can do to intervene.

FLATOW: And so you're saying the earlier the intervention, the better?

Dr. FAUCI: Well, it depends on - there are preventive interventions. And we need to know how a vaccine or a pre-exposure prophylaxis works, how circumcision works, how the gels that we're going to talk about in a minute or two work during those very early events.

There's also the concept that was discussed in great detail at the meeting about early treatment. Namely, what I'm just mentioning now is how to prevent getting that infection initiated.

But once it's initiated, there's a lot of good data that's indicating that the earlier you start therapy, the better off you are from the standpoint of not allowing the virus to form a non-eradicable reservoir, namely such a reservoir that even if you stop therapy after years, the virus is still there, and how you can prevent the really progressive destruction of the immune system, which takes place over years.

So there are a lot of good reasons to try, if possible, to get people on therapy as early as you possibly can if you have the resources and the capability of doing that.

FLATOW: Let's talk about that gel. Tell us what it is made of and how it is used and what are the results.

Dr. FAUCI: Well, it was a study that was conducted in South Africa, and what it did is it gave women a gel that can be inserted into the vagina that's either a gel with no medication in it, which was the placebo, or a gel which contained a one-percent solution of a well-known anti-HIV drug.

And the women were instructed to use it within hours before sexual intercourse and within 12 hours after sexual intercourse. And it was the first study - we refer to this prevention modality as a topical microbicide. It is the first study over many years that we've been trying that showed a very clearcut capability of preventing the acquisition of infection. And it really generated a lot of, I believe, justifiable excitement and enthusiasm in that this prevention modality has never been shown before.

It's important because women now will have, as we move along, the capability of taking prevention into their own hands. Because in many countries, particularly in the developing world, women are not empowered to negotiate the protective means that they need, like the use of a condom by their male partner.

So if we can get this type of thing going, which it will, I believe, it's a question of the study was very robust, the data were good. We need to do, obviously, another study to confirm it, and we need to see how to optimize the use of this gel, but there's no doubt that the data were very clearcut. And that's the reason why there was so much enthusiasm about it at the meeting in Vienna.

FLATOW: Dr. Fenton, do you think there would be use for a gel or this gel here in the United States?

Dr. FENTON: Absolutely. You know, HIV has taken a devastating toll in the United States. And we know that women, especially minority women and African-American women in particular, bear a disproportionate burden of HIV in the U.S.

So again for the reasons that Dr. Fauci has mentioned, having female-controlled methods, having methods that can be optimized and combined with other effective prevention strategies, would be wonderful tools to be able to be used in the U.S. once the regulation restriction and further studies are available.

FLATOW: You presented new research at the meeting that shows that many low-income, urban areas have HIV epidemics. We don't think of having HIV epidemics in this country.

Dr. FENTON: That's correct. You know, when we think of the national prevalence of HIV in the United States, that's approximately 0.4 or 0.5 percent, still higher than some other Western, industrialized countries, but nowhere near some of the prevalences that we hear about from sub-Saharan Africa or parts of Southeast Asia.

But what this first-of-a-kind CDC study showed was that in 23 cities across the United States, when we looked at high poverty areas, we found that the prevalence of HIV was in excess of one percent. In fact, the prevalence was 2.1 percent in these 23 cities, much higher than what we usually term a generalized epidemic, which is one percent.

FLATOW: Your study just looked at heterosexual infection rates. Why was that?

Dr. FENTON: Because one of the things we wanted to do was to exclude from the analysis other high-risk populations which have historically high prevalence of disease. For example, men who have sex with men and injecting drug users.

So what the study really shows is even when you exclude those high-risk populations from these high-prevalence poverty areas, we're still seeing high prevalences of HIV. And that means that the level of HIV in these jurisdictions are enough, is enough to sustain onward transmission of HIV in the poorest parts of the United States.

And this is the first time we've done such a large and comprehensive study covering the entire U.S. to really demonstrate the impact of poverty, race and HIV risk.

FLATOW: Did the risks cross all ethnic and racial lines, it just depends on the poverty level?

Dr. FENTON: Well, this is another fantastic finding in this study, which was even when you adjusted for poverty in these areas or low socioeconomic status, the relationship between race and HIV risk disappeared.

For example, the prevalence among blacks in these high-poverty areas was 2.1 percent. In Hispanics, it was also 2.1 percent, and in whites, it was 1.7 percent.

Now, these prevalences are unacceptable, but what it does say is that in these poor areas, the strongest determinant of HIV risk is not the individual's racial or ethnic background, but it's the low socioeconomic status which is driving other risk factors for HIV.

FLATOW: Such as?

Dr. FENTON: So factors such as poor access to curative services, access to high-quality services. Of course, in many poor areas of the United States, you know that there are high incarceration rates. And there may be other risk behaviors such as transactional sex, commercial sex work, which can put individuals or communities at high risk of acquiring HIV.

FLATOW: Dr. Fauci, does this indicate that we have become complacent or too complacent about HIV in this country?

Dr. FAUCI: Well, certainly there are certain groups of people throughout the country who it has gotten off their radar screen. We've had HIV to our awareness since the summer of 1981. We've made major strides in treatment.

We have an unacceptably high incidence rate. We used to have 120 to 130,000 new infections each year, back in the '80s and early '90s. It's now down to 56,000 per year, but that 56,000, Ira, has been that way for almost 10 years, which means we've reached a wall where we need to go beyond. And that's the reason why, with the CDC's new pushing, and I think it's very appropriate and very important to try and get as many people tested as you possibly can on a voluntary basis for a number of reasons: One, getting the people into therapy who would need therapy and counseling people.

It's a shame, but in this country, of the 1.1 million people who are infected, 21 percent of them do not know that they are infected. And those are the ones that are most likely to infect others.

So there is this degree that, well, we don't necessarily have a problem because you hear of all the staggering statistics from the developing world. But as Dr. Fenton has just mentioned, when you look at the statistics in certain populations in which there are health disparities, as he mentioned, then you really get shocked into seeing that we really do still have a significant problem in this country.

FLATOW: We're going to take a short break and come back and talk lots more with Dr. Kevin Fenton, Dr. Anthony Fauci. Our number is 1-800-989-8255 if you'd like to talk about HIV and AIDS. Maybe you have a question or two you'd like to put to them. Also, you can tweet us, @scifri, @-S-C-I-F-R-I, a question or two if you'd like. Also, go over to our website sciencefriday.com where we're having a discussion online there, and you can leave a comment.

So stay with us. We'll be right back after this short break with Dr. Kevin Fenton, Dr. Anthony Fauci and your questions, 1-800-989-8255.

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FLATOW: I'm Ira Flatow. This is SCIENCE FRIDAY from NPR.

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FLATOW: You're listening to SCIENCE FRIDAY from NPR. I'm Ira Flatow. We're talking this hour about the conclusion of the AIDS conference in Vienna, Austria, with Dr. Anthony Fauci over there, director of the National Institute of Allergy and Infectious Diseases. Dr. Kevin Fenton is director of the National Center for HIV/AIDS, and Viral Hepatitis, STD, and TB Prevention at the Centers for Disease Control and Prevention.

Our number, 1-800-989-8255. Dr. Fenton, earlier this month, President Obama laid out a new domestic AIDS policy. Will that aim at this epidemic of AIDS in the poor communities around America?

Dr. FENTON: I am very convinced that it will. You know, this is the first national strategy that we've had which really provides a strategic vision and goal for ending the epidemic of HIV in the United States.

And the president in this strategy has identified three overarching priorities, the first being reducing HIV incidence in the United States, the second being to reduce health disparities and promoting health equity when it comes to HIV, and the third is really focused on improving access to high-quality health services.

So all three of those priorities will have a significant impact on the work that we need to do in terms of prevention approaches that move beyond individual-level risk to address some of the environmental, social and structural factors which are driving HIV in the U.S. today.

FLATOW: Here's an interesting tweet that came in from Doug Yeager(ph), who says: Could the antiviral in the gel be added to the lubricants in condoms? Dr. Fauci?

Dr. FAUCI: No. You don't want to put any lubricants on condoms because that generally tends to make them break. A condom is a physical barrier, and the physical barrier is all you need. If the physical barrier is intact, then you're good to go.

You don't need nor would want an anti-viral layer. So I would be afraid of getting solutions, and sometimes people do that, put some types of lubricants on, and that really does not do good for the integrity of the condom. So you keep the gel, when you have it, in a situation where you add an antiviral, which as I just mentioned earlier, worked very well.

FLATOW: Let's go to Louis(ph) in Bethesda, Maryland. Hi, Louis.

LOUIS (Caller): Hi, thank you. I love your show. Thanks for having me.

FLATOW: Thank you.

LOUIS: My question was, you discussed that men who sleep with men have a higher risk, but you didn't discuss, when you were talking about how HIV infects vaginally and about the topical creams that could be used, you didn't talk about that with anal sex, and I was just wondering if you could discuss that.

Dr. FAUCI: Well, the study was performed in heterosexual women. It was a vaginal - the use of microbicides for anal intercourse is not out of the question at all. That was not the study that was reported in Vienna, but in principle, the use of topical microbicides could theoretically work in situations where you have receptive anal intercourse. But the study that was conducted was among heterosexual women in South Africa.

FLATOW: Shawnee(ph) is in Charlotte, North Carolina. Welcome to SCIENCE FRIDAY.

SHAWNEE (Caller): Yes, thank you for taking my call. My question that I had was why - how do we come to the decision to use South Africa as a population to test the gel compared to other developing countries, such as India or even South Asia?

Dr. FAUCI: Well, the reason that South Africa was chosen is that the sites that had been developed which had a very good handle on the incidence and had people who were coming to the clinic, were developed by the South African investigators.

So this was not just our parachuting into a country, as it were, and deciding we're going to do a study there. This was conducted by South African investigators, and the report that took place in Vienna was reported by the South African investigators.

The study was using NIH-funded sites, and the study itself was funded by USAID. So it isn't as if we chose Africa. Those were the ones who came up with the idea. They had a population of individuals there who were in dire need of a topical microbicide. So it was very relevant for them.

I might mention that there are studies going on in a number of other countries, including in Asia. So this microbicide study is the one that was reported but there are a number of other studies going on.

SHAWNEE: Oh, wonderful. Thank you very much.

FLATOW: So, but we would have to further study, conduct tests in this country before the gel would be available.

Dr. FAUCI: Well, what usually is the case, Ira, is that the FDA, our regulatory authority, when they make a decision about the use of any intervention, particularly if you're using it in healthy people, it's not therapeutic, you want to make sure about safety, and you want to be absolutely sure it works.

Even though, as I mentioned earlier, the data look quite robust and quite good, in general, the FDA would like a confirmatory study both for the safety and for the efficacy and to get that percentage of efficacy up.

Now, we were discussing this in Vienna that it is conceivable that in some countries in which the incidence and prevalence are much, much higher than in this country, where the health authorities may feel that given the situation that they have, they may want to roll this out as quickly as they possibly can.

Now, the material is not ready to go and put on the shelf, but I can assure you that there will be some countries that will move more rapidly on this because of the individual needs in that country. And, in fact, the South African health minister had mentioned that he was very enthusiastic about this and he would like to move as quickly and as expeditiously as possible, within reason.

FLATOW: 1-800-989-8255. There was another bit of good news from the meeting that more people than ever are receiving the antiretroviral therapies. The numbers are up, Dr. Fauci.

Dr. FAUCI: Yeah, they are. They're indeed up. There's - we were talking about - just a month or so ago, about four million people on therapy. There are now over five million people. That's really a testimony to a number of things, including the extraordinary impact of the president's emergency plan for AIDS relief, the PEPFAR program that was started under President Bush and continued under President Obama, the Global Fund, the Clinton Foundation, the Gates Foundation, and the number of the governments themselves.

The South African government made a really nice presentation about what their plans are in enhancing the availability of drugs for a larger number of people in their population. So the numbers are really going up, and the more we can get on treatment, the better.

FLATOW: Dr. Fenton, what about funding for HIV research in this country under President Obama's new plan, is it adequate? I never heard a researcher say any amount of funding was adequate before.

(Soundbite of laughter)

FLATOW: So I don't expect you to say so either.

Dr. FENTON: Well, you know, and it's great that Dr. Fauci is on the line because NIH does have quite a bit of the share of the HIV research monies. But certainly from CDC's perspective, we have an active interest in looking at research to build the prevention toolkit, to ensure that we're continuing to expand with effective interventions or new tools to fight the epidemic. And that will require resources.

But we also recognize that these are very tough times economically, and so therefore, while building the investment pool, we're also at CDC looking at ways in which we can partner more effectively, to look at using our resources more efficiently to ensure that we're doing the research that's needed to help us to get ahead of the curve in the United States.

FLATOW: Well, would I be correct in saying that what you're saying is that you're not getting an increase in funding, but you'll make do with what you have?

Dr. FENTON: What I am saying is there are needs, and we need to continue to invest in research. That has to be a priority moving forward. But in the meantime, we have to also build our programs and use our resources even more effectively.

FLATOW: That's why you sit in that chair, and I sit in my chair because I could never put it in that perspective. 1-800-989-8255. So Dr. Fauci, where do we stand in the war against AIDS and HIV now? Where is the front line? Besides the pockets of poverty and the epidemics we have here, are we any closer? Was there any talk about a vaccine?

Dr. FAUCI: Yes, there is some good news about vaccine over the past 18 months and even most recently as a few weeks ago. You know, Ira, we had discussed actually on the show, that's some time ago, about a year and a half ago, there was the first trial that took place in Thailand that showed the first inkling of some success in blocking acquisition in a trial of 16,000 people in Thailand. It was a very modest effect, about 31 percent, but it was the first positive signal.

What we had a couple of weeks ago, two to three weeks ago, was the description of the identification in some patients of antibodies that when you look at what they can do - and those are the proteins that the body makes to block the virus - that there are antibodies now that have been identified that can actually knock out or block more than 90 percent of the known strains of HIV.

And you might ask, why is that important with regard to a vaccine? Because we're using those antibodies to identify the component of the HIV envelope, the outer covering of the virus, that is actually the critical part that you want to make an antibody against.

And once we know that, which we do, the task now is how do you get that into form that when you inject it into someone, it will induce an immune response that will actually make those antibodies that we know are highly protective. So we don't have it in our hand yet, but it's an important conceptual advance.

So as the months go by, as the years go by, we are clearly getting closer and closer. One cannot give a date of when we'll have a vaccine, but I feel much more confident today that we will get an HIV vaccine than I did a couple of years ago.

FLATOW: That's good to hear and I think that's a good place to let this go and thank both of you for taking time to be with us today.

Dr. FAUCI: Good to be here.

Dr. FENTON: Thank you.

FLATOW: You're welcome. Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, NIH. Kevin Fenton, director of the National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention at the Centers for Disease Control and Prevention in Atlanta.

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