A radical new strategy for fighting HIV-AIDS

December 04, 2008

    Sorry to disappoint you, but we’re doing a deadly serious topic this week. And I mean that literally, as well as figuratively. Over the past three decades, the AIDS pandemic has become one of the biggest health crises in the history of our planet. According to the U.K.-based humanitarian group AVERT, the disease already has killed more than 25 million people, and an estimated 33 million more are infected with HIV, the virus that causes it. Alarmingly, despite international public health efforts to stem the spread of the disease —such as the promotion of safe sex and attempts to curb needle sharing by IV drug users  —  an estimated 2.7 million more people become infected annually worldwide. Scientists have managed to develop antiretroviral therapy (ART) that, if taken conscientiously on a daily basis, can keep the amount of HIV in the body low and, in a best-case scenario, may enable a person to live for many years without becoming ill.

But wait, there's more...

But virtually everyone has assumed the real answer to HIV-AIDS would come when scientists eventually developed a silver bullet — an anti-HIV vaccine that would prevent a person from becoming infected, and/or would help the body of an infected person to kill the virus. But after 20 years of research, the effort is pretty much stymied, after the failed clinical trial of Merck’s V520 experimental vaccine. In a Scientific American interview this summer, Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, admitted that researchers are “swimming in the dark,” and explained why such a vaccine has proven so elusive.

Astoundingly, of the tens of millions of people who have been infected, there's not a single documented case of someone who has established infection and ultimately eradicates the virus from the body. There are a number of people who are what we call "long-term nonprogressors"—for one reason or another, perhaps their genetic makeup, they seem to handle the virus reasonably well for a long period of time. For the overwhelming majority of people, the virus ultimately overcomes their immune system's attempts to curtail the virus. So, we are dealing with a situation where we don't even know if the body is capable of eliciting a protective immune response. And if it can, we know it's very difficult, because when you look at infected people, it is so unusual to see people with very good, broadly reacting neutralizing antibodies. So, when you go after developing a vaccine for HIV, you're in an entirely different ballpark than you are when you're trying to develop a vaccine for influenza or smallpox or polio or measles.

We as a field didn't fully appreciate that early on, as a matter of fact. That's the reason why it would be an understandable statement, though now retrospectively clearly premature, to say, "Okay, we have the virus in our hand, we are growing it, we know what it is. It should be a snap to develop a vaccine." Now we know that this just is not the case, so our challenge for the future is to do much better than what natural infection does because natural infection clearly is not successful in inducing an ultimately protective response.

    Sounds grim, doesn’t it? But maybe not. A team of World Health Organization researchers led by physician and biostatistician Reuben M. Granich have just published a  study in the Lancet, a prestigious British medical journal, which suggests a completely different approach. In a greatly oversimplified version, here it is: What if we got everyone — or at least, everyone in developing countries with high HIV infection rates  —   to voluntarily take an HIV test, and then immediately began treating everyone who tested positive with ART, even if they weren’t yet sick? Could such super-aggressive screening and treatment stop the disease’s spread, even without a vaccine? The logic behind this action plan is that treating infected people with antiretroviral drugs can dramatically decrease the “viral load,” i.e. the amount of the virus in their bloodstreams — a major factor in the risk of both heterosexual HIV transmission and mother-to-child transmission of HIV.
    The researchers used data from South Africa  — a nation where about one in five adults is infected, due in large part to in-denial government  —  as a test case for a generalized epidemic.  When they ran the statistical modeling, the results were startling. An an Associated Press story  on the study distills the key points:

Within 10 years, HIV infections dropped by 95 percent. Other initiatives like safe sex education and male circumcision were also used. The strategy would cut the estimated number of AIDS deaths between 2008 and 2050 by about half, from about 8.7 million to 3.9 million, leaving only sporadic HIV cases.

Charles F. Gilks, one of the study’s authors and the chairman of the international health program at Imperial College in London, told the AP:

"In a relatively short amount of time, we could potentially knock the epidemic on its head."

   

    As the Washington Post notes, attacking HIV-AIDS in this energetic fashion might actually cost less, in the long run, than the existing approach:

The strategy would require large up-front investment in testing and treatment but would eventually cost less than the current strategy of putting off treatment until the infection has advanced because so many new infections would be averted. The model assumes testing, drugs and clinical management would cost about $730 a year per patient with first-line drugs, and $3,300 when a person switched to more expensive second-line drugs. By 2032, the cost of the current strategy or delayed treatment and the cost of universal treatment would be about the same: $1.7 billion a year.

    But such a bold idea is not without some downsides. Handing out antiretroviral drugs to everyone who tests positive might accelerate the rise of drug-resistant strains of HIV. Already, public health experts are worried about the prospect of HIV mutating to become resistant to nevirapine, a medication widely used in developing countries to prevent mother-to-child HIV transmission.

Others question whether advising HIV positive people to start treatment immediately, even if they aren’t sick, is ethical, since it may benefit the population as a whole more than it benefits an individual patient. Long-term use of antiretroviral drugs, after all, is known to have potentially dangerous side effects, including liver and muscle cell damage and cardiovascular problems. And because people in developing countries are more likely to suffer also from conditions such as anemia, malnutrition and tuberculosis, they run a higher risk of jeopardizing their health from participating in ART than people in the U.S. and Western Europe do.  It also should be mentioned that getting ART reduces, but doesn’t totally eliminate, the risk of transmitting the virus to someone else. So even if a massive anti-HIV treatment campaign is waged, it’ll still be critical to promote condom use and convince IV drug addicts not to share needles, among other measures.

So what do you think? Is the test-everybody, treat-everybody strategy the way to go? Or should we continue to hold out our hopes for that elusive HIV vaccine? Express your opinion below.

Comments

[Adam]

This is a great idea, but I wonder if anyone really thinks that there's a realistic chance of gathering the funding and political will to carry out such a project. Sadly, the reality is that even if the resources were available, it would be nearly impossible to ensure that the funds and medication got to where they were needed because of the rampant corruption and lack of infrastructure over much of Africa.

[Caffeine Driven Stress Magnet]

You're right about the level of corruption in Africa, but I still think this plan might work. PEPFAR, the Bush Administration's anti-AIDS effort, seems to have been pretty successful in increasing the amount of retroviral treatment for Africans with HIV. And the amount of money being spent on PEPFAR is really not that huge--it's far less, for example, than the amount being wasted on a stealth destroyer that the Navy doesn't really need.

[Patrick Kiger]

I think the potential pitfall that concerns me the most is the possibility that more aggressive use of ART may accelerate the development of drug-resistant strains of HIV. Does anyone out there have some knowledge about this that they could share?

[Raymond]

New drug-resistant strains of HIV are showing up in China, where the problem apparently is caused by the fact that they don't have as many different kinds of antiviral drugs as the U.S. and Europe do.

http://www.reuters.com/article/healthNews/idUSTRE4992BT20081010

[Patriot]

I think we need to let these African countries work to solve their own problems. They aren't going to embrace solutions that we give them or order them to do. We've got plenty of pressing problems here in the US to work on, like the need to build more nuclear power plants to solve our energy problems.

[Leander]

Aside from creating drug-resistant strains, the particularly nasty side-effects of the medications especially given long-term usage, how do you get the masses to voluntarily be tested? Barring mandates, most people don't feel obligated to give up certain freedoms (such as privacy, the ability to do very stupid things with their lives, ect.), especially without getting something in return. This bring us back to mandating the testing...anyone here care to have your freedoms trampled?

[Manny]

I don't think that people will turn down the immediate drug treatment if they are told that they may die otherwise. That may not be totally honest, but it's in the public good.

[Marianne Bach]

That would be incredibly unethical and a complete violation of patients' rights.

[Manny]

How would saving their lives be unethical?

[Gin]

well i think that this can be the people choice to either take it or not. if its not forced upon them and they decide to take the risk of such treatment then i guess its alright. although HIV aids is really a pressing matter in which there is no right or wrong way to go.
but as they said decreasing the viral load within the blood stream is a way to decrease chances or if they can re-strain or isolate the virus, i guess go for it in order to buy time to actually find a solution for this problem.

[Patrick Kiger]

Reducing the viral load in a patient decreases the risk of transmission, but doesn't eliminate it. Here's a 2008 study from the Lancet http://www.thelancet.com/journals/lancet/article/PIIS0140673608611150/fulltext
that concludes:

Our analyses suggest that the risk of HIV transmission in heterosexual partnerships in the presence of effective treatment is low but non-zero and that the transmission risk in male homosexual partnerships is high over repeated exposures. If the claim of non-infectiousness in effectively treated patients was widely accepted, and condom use subsequently declined, then there is the potential for substantial increases in HIV incidence.

[Mike Brown]

So that's what you look like. I was picturing a Malcolm Gladwell-style unruly bird-nest hairdo look.

[Kasado]

It's amazing. We have known about AIDS and how its transmitted since 1985 and still we have no cure. Modern medicine has only found a way to extend the lives of the infected to ensure that they are able to reinfect others. I believe the only way to destroy this virus is to GIVE UP and let the disease naturally run its course. Pain killers can be administered, but by medicating the problem we only prolong the pain and suffering that we are trying to halt.