Scientists discover (again): AIDS treatment prevents infection

Flickr, Benny Sølz

As MSNBC, the Wall Street Journal, New York Times and many other media report today:

People infected with the virus that causes AIDS are far less likely to infect their sexual partners if they are put on treatment immediately instead of waiting until their immune systems begin to deteriorate, scientists report.

The study, begun in 2005, was done by the National Institutes of Health and had such dramatically positive results it was ended five years early. As the Wall Street Journal’s Mark Schoofs writes:

The results were so overwhelming that an independent panel monitoring the research recommended the results be released four years before the large, multi-country study had been scheduled to end.


Connie Celum

What may be even more surprising is that a Seattle-based AIDS expert, Connie Celum, as well as some Swiss scientists had already discovered this!

Here’s my post on Celum’s findings last July, UW Study shows AIDS Treatment IS Prevention. As Celum and her team reported back then in The Lancet:

“We found a 92 percent reduction in transmission among those who went on (anti-HIV drug therapy),” said Celum.

The New York Times said the NIH study was convincing because it is the first time this was shown in a major randomized clinical trial and earlier studies had only “implied” this. That’s a little misleading and certainly ignores the power of what Celum and her colleagues showed.

The UW team studied 3,400 couples in seven African countries (Botswana, Kenya, Rwanda, South Africa, Tanzania, Uganda and Zambia) and followed 349 couples for two years after the HIV-infected partner started taking the drugs. Those who remained on the medication therapy reduced their chances of passing on HIV to the sexual partner by 92 percent — pretty much what NIH found.

In 2008, when some Swiss scientists first suggested this idea based on a number of studies they believed clearly showed that treatment actually is prevention many American AIDS experts dismissed the notion, one even calling it “dangerous.”

“Not only is [the Swiss proposal]dangerous, it’s misleading and it is not considering the implications of the biological facts involved with HIV transmission,” said Dr. Jay Levy, director of the Laboratory for Tumor and AIDS Virus Research at the University of California in San Francisco and one of the co-discoverers of HIV.

This finding/confirmation that treating people with HIV is highly effective at preventing the spread of AIDS has profound implications for AIDS care in the U.S. but also for global health.

  • First, it gets round the whole prevention vs. treatment debate — since they now accomplish the same thing.
  • Secondly, it implies that the best strategy for battling the HIV pandemic in lieu of an effective AIDS vaccine is to aggressively identify all of those infected and get them on treatment as soon as possible.

Some experts believe the HIV pandemic — which continues to newly infect millions of people and costs the international community tens of billions of dollars today — could be brought to heel in five years if those at risk were aggressively tested and treated.

Standard procedure for starting anti-HIV drugs is based on when the blood level of an immune cell targeted by HIV, known as the CD4 cell, drops below a certain threshold. In most African countries, that threshold is a CD4 count of 200 or lower (normal being from 500 to 1,000). Now, it looks like drug therapy should begin as soon as HIV is detected.

As Celum told me today: “Maybe this will be the final piece of data to stimulate policymakers to take note and push for more resources.”

Paying for this up front will be painful, but the cost of not doing it will be more so.


About Author

Tom Paulson

Tom Paulson is founder and lead journalist at Humanosphere. Prior to operating this online news site, he reported on science,  medicine, health policy, aid and development for the Seattle Post-Intelligencer. Contact him at tom[at] or follow him on Twitter @tompaulson.

  • Soon there will be nobody left out of treatment. Time to move forward with what we know works. Okay, so far we are not that good at delivering ART with less than 39% of those who need it according to current guideline receiving it, but the challenge is only operational. If Coke can deliver its product worldwide, we should be able to do the same with life saving medicine. It about will and commitment.

  • Starting ART as soon as HIV is detected? Don’t think so.

    Besides the question of whether starting ART early is in the interests of individual people with HIV (or whether it would encourage ART resistance to develop much faster, including in individuals), I don’t think you are thinking through the numbers here.

    In early 2010, WHO changed their ART treatment threshold recommendations from <200 CD4 to <350. That already threw all the ART-counters into a spin because it suddenly meant that the number of people 'eligible' for ART went up significantly overnight, and coverage figures dropped as quickly.

    Now you are suggesting that all 33.3 million people living with HIV should be 'eligible' for ART – if they started ART as soon as HIV is detected. That would mean that current ART coverage would drop from the current 40% of those who 'need' ART to about 16% (i.e. 5.2 m out of 33.3 m) – a much lower starting point for global coverage.

    Going from 16% coverage to anything like 100% after what has already been a decade or so of the most intensive health programme ever launched (to expand ART) is just not going to happen in today's global health, financial and political environment.

    • Thanks Tim,

      You and “Northeasterner” above make some excellent points about the reality of attempting to expand ART treatment to  many more people earlier in their stage of infection. All I can say is that other experts are calling for getting many more people on treatment as a result of these findings. And I will note that many said, years ago, that it wouldn’t have been possible to widely distribute anti-HIV drugs in poor parts of Africa due to the complexity of the drug regimen, lack of laboratory and health services and all that. But they did.

  • Northeasterner

    This has exciting potential for HICs but in places like India (where I am doing HIV work) it faces plenty of issues in implementation:

    1 – The ART used in the trial was NOT the cheaper drugs widely used here which have many more side effects. Asking people to suffer an additional 5-15 years of side effects at no direct benefit to themselves would inevitably affect acceptability and adherence to treatment.

    2 – As previously pointed out, we are just not that good at providing ART when and where it’s needed. This is not going to change quickly, nor is the funding required for a massive scale-up of coverage likely to materialise quickly, particularly at a time when donors are turning their attention to other causes

    3 – Using ART as prevention requires regular and easily available testing, a situation that is yet to materialise in many parts of the world. Unless people are quickly tested after each exposure, or regularly tested if consistently at risk, there could be many months or years of exposing others to risk after someone becomes infected. Promoting safer sex, by contrast, is not dependent on knowing the person’s status and has additional benefits in preventing other STIs and reducing unplanned pregnancies.

    4 – At least in India, the stigma attached to HIV and ART is such that ART uptake is relatively low even among confirmed PLWHA. If ART were to be considered as an alternative prevention strategy for people who didn’t want to alert their sexual partners ot their status by insisting on condoms, there would first need to be a radical change in the way ART is distributed to allow for greater confidentiality. The best strategy is still to address the stigma that drives this but it is very slow going.

    In short, this is no magic bullet, but like circumcision, gels, vaccines, condoms and all the other measures once touted as our salvation it will go into the toolkit as another useful strategy. I certainly hope on the advocacy level it gives governments one more reason to push hard on ART delivery.