HIV Vaccine May Be on the Horizon

vaccineThe exciting news this morning is that trials of a new HIV vaccine have shown promising results, and an HIV vaccine could be just around the corner. According to CNN:

The new study was conducted in Thailand, with more than 16,000 people between ages 18 and 30 participating. They were all HIV negative at the beginning of the trial.

Nearly 8,200 received a placebo and a similar number received a combination of six vaccines over six months. All were followed for three years.

Researchers found that those who received the vaccine combination were 31 percent less likely to contract HIV compared with those on a placebo.

“This shows a statistically significant effect,” Kim said.

The Washington Post was a little more downbeat in it’s coverage, calling the tests “barely statistically significant.” However, they did note that these trials show that an HIV vaccine is possible, whereas previous tests were not as hopeful.

“Conceptually, we now know a vaccine is possible,” said Anthony S. Fauci, director of the National Institute of Allergy and Infectious Diseases, which paid for most of the six-year trial. “Whether the vaccine is going to look anything like this one I don’t know. But at least we know it can be done.”

The vaccine is not licensed or being produced in large amounts. It is unlikely — but not impossible — that any country would consider it effective enough to be used as a public health measure against HIV.

Instead, the chief usefulness of the so-called ALVAC-AIDSVAX vaccine is likely to be what it can teach virologists about what is happening in the immune system when a person is even somewhat protected from HIV.

There is one question that both of these articles fails to ask: what were the controlling factors in this study? (Remember my post about “abortion trauma syndrome“? I can’t help it – I like picking apart statistics.) How likely were the study’s participants to practice safer sex? Were the participants from a “high risk” group, such as sex workers or gay men? Which sexual acts did the participants engage in? I think that the study needs to control for all of these factors in order for the 31% reduction in HIV transmission to be valid. How do we know that the people who didn’t contract HIV remained negative because of the vaccine, and not because they were using condoms every time?

I’m not trying to rain on any parades. Obviously a vaccine for HIV is a great piece of news to start your day with. Here’s to hoping that future trials will yield even more statistically significant results.

Photo credit: stock.xchng

Comments

  1. The study was conducted, in part, by the same folks who conducted the Phase 3 AIDSVAX studies in the early 2000s (former VaxGen employees working at GSID). The subjects in these early studies were at high risk (IV drug users, gay men, sex workers) for contracting HIV. Sadly, the Phase 3 studies did not show any significant protection offered by the AIDSVAX vaccine alone. One significant outcome from the failed Phase 3 studies was that it taught us how to conduct these studies, which are really quite difficult to carry out. Presumably the latest studies were well thought out and the right mix of subjects were included.

    The latest studies probably won’t directly result in a vaccine against HIV, but, like the failed Phase 3 studies, will hopefully lead us down the right path towards a vaccine, and maybe even a cure. I don’t think you are raining on any parades- the media tend to hype this stuff up, and we, the readers, have a responsibility to suss out the truth from the hype.

  2. One other thing to consider in terms of your questions–There have been HIV Vaccine trials of various stripes for over 20 years, most, if not all, have included safer sex counseling and handing out of free condoms to study participants. Still, with that being the case, this is the first study to have a scientifically significant result of reduced infections.

    Your questions are good, and so are the others that I have encountered. Asking questions also helps keep the conversation going. Like Michelle said, this study isn’t the vaccine, but is another step to getting us closer to a vaccine and/or a cure. It teaches us more about the virus and the human body. And even when the vaccine is discovered, it will still only be PART of a whole host of HIV treatments and preventions.

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