Another experimental AIDS vaccine fails, but that’s progess in science | 

Vaccine
by hitthatswitch, Flickr

Federal health officials announced this week that they were pulling the plug early on a study of an experimental AIDS vaccine (known as HVTN 505) due to evidence the vaccine didn’t protect against HIV infection.

The news reports were bleak:

NPR Failure of latest HIV vaccine test a huge disappointment

LA Times HIV vaccine trial shut down

US News & World Report HIV vaccine recipients more likely to catch virus

It’s bad news since the only way we are likely to ever fully prevent HIV infection will be when we get an effective vaccine. And there is scientific evidence that an AIDS vaccine is possible, as I reported on regarding a clinical trial done in Thailand (pre-Humanosphere and post newspaper career) years ago for the Aids Vaccine Advocacy Coalition. They paid me to do it, but the reporting was done with full editorial control and independence.

But there’s another way to look at this – as progress, actually. Because science is actually often all about finding some useful facts from a failure.

Julie McElrath
Julie McElrath

“We’re all disappointed, but it’s important to note that we will still learn something from this study,” said Julie McElrath, head of the Seattle trials unit for the HVTN, HIV Vaccine Trials Network (which is headquartered in Seattle, at Fred Hutchinson Cancer Research Center). “A definitive answer, whether yes or no, is progress.”  

The AIDS vaccine trial in Thailand, known as RV 144, stunned many because expectations for it were so low and, for many years, all we had been hearing out of these AIDS vaccine trials was bad news. In the Thai trial, we didn’t get a vaccine that was effective enough for prime time; but we did get some protection against HIV infection, enough to provide enticing evidence that a vaccine is do-able.

Part of the problem, as I reported, with the RV 144 trial was that because so few expected it to work the Thai government didn’t really do a very good job at collecting samples and monitoring its progress. This latest trial, HVTN 505,  was distinctly different from the Thai vaccine, though similar in that it was a combo approach. But it used a very different combination of vaccine and ‘booster’ which included a modified adenovirus (cold virus) that has now clearly been proven ineffective – or worse.

It didn’t work and, though statistically insignificant, those who got the vaccine had a slightly higher rate of HIV infection than those getting placebo.

Hence the headlines, which we’ve seen before in another AIDS vaccine trial known as STEP, implying that the vaccine actually put people at higher risk (unknown).

“So I think we can say now, definitively, that this approach is not the one to move forward with,” said McElrath. There are other strategies to be explored, she said, including a plan to launch a new trial based on what was learned from the Thai RV 144 trial.

So a more informed response to the bad news with this AIDS vaccine is to recognize we’re actually in about the same place we were before we got this bad news – still trying to take what we learned from RV 144 and figure out what, in that trial, appeared to work.

Failure is a big part of the scientific method. It is, in fact, most of the scientific method. Dealing with failure and accepting uncertainty is the nature of this task, as one of the central players — and administrators of this trial — told me a few months ago.

James Kublin
James Kublin
FHCRC

“We actually don’t know what the agenda is,” said Dr. Jim Kublin, executive director of the HIV Vaccine Trials Network (HVTN) based at Seattle’s Fred Hutchinson Cancer Research Center.

That drew a lot of laughs from the audience, since Kublin’s lecture title for the day was ‘Scientific Agenda, the Next Seven Years.’

The problem for scientists is that the public and donors, especially American ones, are impatient and want results now. Kublin says many of the donors and aid agencies that once supported HIV vaccine research have drifted away in search of more certain, short-term success stories. Many funders, he said, seem to be taking more of an industrial or commercial approach by demanding specific goals and milestones.

“That’s not good for science,” Kublin said. “For science to make progress, you have to embrace uncertainty. Many donors don’t like that and that’s a problem for us.”

  • Bobbi Nodell

    Best coverage so far on this story!