An AIDS Vaccine is Now More than a Dream

The elusive dream of an AIDS vaccine is one step closer to reality. Last week an historic announcement was made in Thailand: the world's largest HIV prevention trial showed that an AIDS vaccine is possible.

And it also seemed to prove that science at its most exhilarating is unpredictable and downright surprising. Before it even enrolled the first of its 16,400 volunteers, the Thai prime-boost trial was labeled a guaranteed failure by critics, many of whom questioned its design and whether it should go forward at all.

Five years later, thanks to the dedication of the volunteers, trial staff and sponsors, we have the exciting news that the vaccine regimen is the first in history to show an impact on risk of HIV infection. The protective effect -- roughly 30 percent -- is modest, to be sure. In the weeks and months to come there will be difficult questions about what the next steps should be in terms of research on this strategy and on the entire AIDS vaccine field as a whole.

But before embarking on this necessary process of questions and, no doubt, debate, the world should take a moment to celebrate an historic finding that many stalwart AIDS vaccine advocates did not believe would come in their lifetimes.

To put it in context, two years ago many people were asking if the dream of an AIDS vaccine was over. Were we wasting millions of dollars on a fruitless search for a vaccine that seemed to grow more and more elusive?

These questions were prompted by news of the failure of what was then seen as the most promising AIDS vaccine candidate to enter clinical trials. The failure of this candidate, MRK-Ad5, demoralized researchers and advocates. In the aftermath, critics within and outside the field questioned the wisdom of conducting any more AIDS vaccine trials in humans and even asked whether an AIDS vaccine was a realistic goal for the HIV prevention field.

In these discussions, the Thai prime-boost trial was frequently an afterthought. It was certainly not expected to be the trial that buoyed hopes and brought to an end the first chapter of AIDS vaccine research twenty years before a proof of concept that a vaccine is possible.

As we celebrate, we must also remember that there are many, many steps from a proof of concept (as demonstrated in this trial) to a licensed vaccine that can be introduced (which is certainly not warranted based on this one trial).

In the near- and mid-term it will be critical that these results are explained to the full range of relevant stakeholders in a balanced and thoughtful way. This is the first step, not the end of the road. As the trial team has made clear, the broader scientific community will need to provide expert input on how these results impact on other vaccine research and on additional research that should be undertaken with this or similar regimens to learn more about it specifically.

The bottom line is that this is both cause for celebration and a complicated result. It doesn't mean that tomorrow the citizens of Thailand or any other country can roll up their sleeves and stand in line to get an AIDS vaccine. We're still a long way from that.

So how do we move from this modest effect in a clinical trial to a tangible public health good?

Additional scientific research and studies are a large piece of a very complex puzzle. But, we have several other herculean tasks ahead of us that will require unprecedented cooperation among researchers, funders, policymakers, advocates and communities.

We must begin to discuss in specific terms what the world might do with a partially effective AIDS vaccine.

Such a vaccine would be enormously valuable as part of a combination approach to HIV prevention. However, most people equate a vaccine with complete protection from a disease, and it will be difficult to convey what a partially effective vaccine would and would not do. Advocates, social scientists and community members must begin to work now to develop ways to explain how a partially effective AIDS vaccine will work along with other prevention methods to help protect individuals from HIV infection.

Pharmaceutical and biotech companies and other partners must think now about manufacturing capacity, both for the doses needed for any new trials of this vaccine combination and for any eventual licensed vaccine, and legislators and funders must determine how we will finance manufacturing and distribution when we eventually do have a vaccine that can be licensed.

Regulatory officials in Thailand and other countries hardest hit by AIDS must develop clear policies and pathways for licensing partially effective vaccines and other new prevention strategies, and policymakers in those countries must develop policies and guidelines for including partially effective AIDS vaccines in their HIV prevention programs.

And we must all redouble our efforts to expand access to existing HIV treatment and prevention programs around the world and to sustain investment in research and development for AIDS vaccines and other biomedical prevention options, including microbicides and pre-exposure prophylaxis (PrEP).

Throughout, advocates must work as aggressively as the researchers to ensure that the perspectives of communities are represented in planning for additional trials and for future access, and we must hold each other accountable for proceeding quickly and transparently.

We still have a long way to go before we can end the AIDS epidemic, but this week's news brought us closer to the finish line.