ARV Drugs Greatly Cut HIV Risk: Chiang Mai University

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ARV drugs greatly cut HIV risk

By Ekkapong Praditpong

The Nation on Sunday

Less gay men catch disease if taking anti-retrovirals

Taking antiretroviral (ARV) drugs could significantly reduce the chances of sexually active gay men getting HIV, the director of Chiang Mai University's Research Institute for Health Sciences (Rihes) Suwat Chariyalertsak said yesterday.

His comment was made to coincide with World Aids Day on Wednesday.

The clinical trial iPrEx (Pre-Exposure Prophylaxis Initiative), whose "ground-breaking" results were published in the New England Journal of Medicine, was a collaboration between Rihes and 11 other top research institutes in six countries.

The trial, led by Dr Robert Grant from the University of California's Gladstone Institute of Virology and Immunology, had 2,499 volunteers in Peru, Ecuador, Brazil, South Africa, the United States and Thailand.

The trial began to take volunteers in mid-2007, but Suwat said Thailand started research in Chiang Mai in early 2009 and continued until August this year. Following the end of medication given in all countries, the researchers would follow up on the volunteers until March next year, he said.

The trial randomly assigned the volunteers - who were men who had sex with men, or transgender women who had sex with men - into two groups. The first group had to take one tablet of Truvada (a combination of two ARV medications, namely TDF and FTC) on a daily basis and the second group had to take a placebo.

They found that, from the beginning until May 1, there were 36 people who became HIV-positive out of 1,251 volunteers who took Truvada, while 64 people out of 1,248 volunteers who took the placebo became HIV-positive. So, statistically it was concluded that the two ARV drugs could help reduce the risk of getting HIV by nearly 44 per cent - compared to the group that took the placebo.

Suwat said in the cases of the volunteers who took the drugs regularly, the prevention rate went up.

Suwat said iPrEx was the third study to find a way to prevent catching the HIV virus, following the HIV/Aids vaccine project that discovered a prevention rate of 31 per cent and the Caprisa 004 trial on tenofovir gel application in South Africa that found a prevention rate of 39 per cent.

With the world still seeing about 2.7 million new infections a year, there was a lot more ongoing research involving more than 20,000 volunteers worldwide, he said. These projects should be finished within two to three years.

-- The Nation 2010-11-28

[geriatrickid]

The headline is inappropriate and misleading.

Headline: ARV drugs greatly cut HIV and Less gay men catch disease if taking anti-retrovirals

What was actually stated:

1. Taking antiretroviral (ARV) drugs could significantly reduce the chances of sexually active gay men getting HIV,

2. ........the researchers would follow up on the volunteers until March next year,

3. ......there was a lot more ongoing research involving more than 20,000 volunteers worldwide, he said. These projects should be finished within two to three years.

No firm statement can be given since the studies are not completed. There is a positive indication, but that's all that it is. What also needs to be done is to determine if the reduction in transmission was due to the counseling or the screening or the monitoring that reinforced safe practices or the drugs themselves. If the drugs were truly effective there would have been no transmissions or an even greater reduction than that reported. One need only look at vaccines for diseases such as polio to understand the difference between success and hopeful signs. If the polio vaccine is administered to high risk groups, the studies show it will effectively reduce the incidence of polio.That is why the vaccine is given. If high risk groups for HIV take the proposed medication, there is a possibility that the infection rate will be reduced. Big, big difference.

One has to balance the cost of administering such medications, the cost of adverse reactions and the cost when unsafe behaviours increase because people assume that if they pop a pill they won't get HIV. All of the HIV medications carry serious side effects, many patients taking them are often in great discomfort or suffer from debilitating side effects. Handing out the pills like candy will create resistant strains and rob those most in need of medication, an opportunity to survive. The medications are expensive.

From a cost benefit perspective, I do not think that the public health agencies will embrace this approach until the other studies are completed and there is definitive proof that a benefit is given that outweighs the danger to the population as a whole. It is hopeful news, but nothing more than that.

[jsflynn603]

I too wonder about prophylactic use of anti-retroviral drugs and potential increased resistance.

The study and its resultant article seems seriously flawed to me, if only by this short statement within the article:

“The total numbers of sexual partners with whom the respondent had receptive anal intercourse decreased, and the percentage of those partners who used a condom increased after subjects enrolled in the study.”

The article says that each participant received “At every scheduled visit, subjects received a comprehensive package of prevention services, including HIV testing, risk-reduction counseling, condoms…” The article tells us that each participant had 8 visits in the first year. (Weeks 0, 4, 8, 16, 24, and every 12 weeks after..).

So one must reduce the 44% reduction of HIV + participants by some amount to allow for the reduction that would normally occur if said counseling were to occur without the use of the pharmacological agent.

If the % of condom use increased and there was a decrease in receptive anal intercourse—what % reduction did this factor alone account for?

The statement: “Conclusion: Oral FTC–TDF provided protection against the acquisition of HIV infection among the subjects,” is probably true—but there is little evidence that the true reduction of infection truly was 44% and it is sad that the authors blithely ignore this fact, and worse, fail to even mention that were such a regime to be readily available that resistant strains would emerge. (See: http://www.medscape.com/viewarticle/564804_6 ) Note: The combination FTC-TDF is considered resistant, but not impervious to the creation of resistant variants of HIV (see article).

What infuriates me and has for 18 years is the fact that many Public Health Agencies, clinics, etc. consistently neglect real and rational advice to those who seek reliable information about the “waiting period” for testing. Go to ten clinics and ask: “How long must I and my partner to be wait before being sure that I am HIV negative so that we can be sure that we are both negative.” Some will say 6 weeks, some will say 2 months, and some might say 6 months or even a year—and who will (and do they really even need) wait six weeks, much less 6 months?

The Elisa test has gone though three generations and the fourth generation was recently approved by the US FDA (though it is not in common use yet). As the years and decades have gone by the “latency” period, during which a person will prove positive if they are infected has decreased. Clinics still will sometimes tell a person, “oh, you can’t be sure for a year.” While this technically true, meaning that perhaps 1 person in 100,000 won’t seroconvert to the level, if infected, before they show a positive test—it does nothing for a couple that’s hot to trot.

A test needs something to test and a certain quantity of that something to “tilt the scales.” 1^st generation Elisa needed a certain quantity of antibodies and the level in an infected person (in 1984) took many, many weeks to show a positive test. The latency period (the time you had to wait after the last potential time of infection) was large—like two or three months (where 99.8% would seroconvert). But second generation and third generation tests reacted faster to lower and lower levels of antibodies such that 99.8% would seroconvert in a shorter period of time. But clinics did not reduce the proposed latency periods told to clients. The newest (as yet not available) Architect Ag/Ab test measures antigens which the body produces faster than antibodies. So the latency period will be even shorter.

The ONLY way (and even then we’re talking 99.9+% sure) that you and your partner is safe to have unprotected sex (speaking HIV only) is to wait without partner fluid transfer through the latency period and then get tested. When and IF clinics start telling clients accurate latency periods is (in my opinion) the only true protective method (barring correct condom use). As long as clinics still act as though the latency period is months—couples are unlikely to wait. If the latency period for the Architect Ag/Ab is, let’s say 18 days where 99.8% seroconvert, well a lot of couples are far more likely to wait the 18 days, and have less than a 0.2% chance of either infecting the other. But if clinics continue to tout 6 or 12 weeks as a waiting period, most couples will simply get it on.

Abstinence is touted the best, and (except for proper use of condoms—which many will not do) it is—but for gosh sake Public Health, and clinics—please start being truthful about latency periods. This will do far more than pie in the sky “prophylactic drug” regimes that will never become widespread.