10/16/2013 01:04 pm ET Updated Dec 16, 2013

AIDS Vaccine Update

Last week's international AIDS Vaccine conference in Barcelona may best be described as a roller coaster ride marked by highs and lows.

Starting with the highs, the 1,000 scientists and advocates at the event celebrated last month's news that an experimental vaccine "cleared" HIV in monkeys infected with the virus. In layman's terms, cleared is as good as cured. And experts remain excited by 2009's RV144 trial in Thailand confirming that an HIV vaccine reduced the risk of infection in people for the first time in history.

This was great news in a 30-year quest for a vaccine that's been marked by failure and frustration. "HIV is a tricky disease to make a vaccine for," sums up William Snow, director of the Global HIV Vaccine Enterprise. "But huge strides are being made."

And being lost: A new analysis, unpublished but unveiled in Barcelona, pointed toward what not only doesn't work but actually causes harm. The pooled results of trials of three failed vaccines confirmed the spectacularly bad news that participants in two of the three who received the vaccine were actually more likely to become infected with the virus than those getting a placebo. Researchers stopped all of these studies once it was clear that the vaccines weren't effective.

Though this wasn't spanking-new news, the analysis marked the first time the data from the STEP, Phambili and HVTN 505 studies, all using a virus related to the common cold, had been examined together.

Two steps forward, one step back.

The conference was also for significant for what was missing -- or who: Some of the world's most important scientists were grounded in the U.S. by the continuing government shutdown. In fact, researchers from the National Institutes of Health, the top funder of AIDS vaccine research, were missing in action.

Dr. Anthony Fauci, head of the NIH's Allergy and Infectious Diseases division, kicked off the conference on Monday via a pre-recorded video. He called the government shutdown "extraordinary" as he highlighted the urgent need for an AIDS vaccine.

Those who did make it to Barcelona agreed. Last year, 2.3 million people around the world were newly infected with HIV, and far too many lack lifesaving treatment. In the United States, 56,000 contract the virus each year, and gay men and transgender women remain at highest risk, especially those who are black. In some communities of color, HIV rates are as high or higher than in areas of Africa, the continent that has been hardest hit by the disease.

Many in the vaccine field hope to build on the recent successes. Next up, a set of studies known as P5 that will test improved vaccine compounds in Thailand and South Africa. "P5 gives a lot of people hope by building on the promise of RV144," says Mitchell Warren, executive director of the AIDS Vaccine Advocacy Coalition.

But even so-called failures can provide teaching moments. "I've failed in an HIV vaccine, so I know it's okay to fail," says Dr. Jerald Sadoff, one of the world's leading vaccine scientists. "But if you succeed in everything, you haven't taken risks. And if don't take risks, you will never succeed."

And what about the time frame? Is it realistic to expect a vaccine in the next 10 years? Maybe. "Over the past 32 years, people have been saying we will have a vaccine in a decade," says Warren. "That's true; it just depends on when we start the clock."

In the meantime, prevention strategies like circumcision, microbicides, pre-exposure prophylaxis (PrEP) and treatment as prevention are speeding ahead of vaccines. Says Steve Wakefield, director of community education for the HIV Trials Network: "A combination of prevention strategies is actually the best hope to end the epidemic."

With that in mind, the AIDS Vaccine conference officially ends a 13-year-run in Barcelona. Beginning next October, scientists and advocates from all prevention disciplines will convene together in Capetown to encourage more "interconnection."

"The way the field is evolving, it's clear that to fight this disease you need multiple interventions," says Galit Alter of the Ragon Institute, an MIT-Harvard partnership. "Even hard-core vaccinologists like myself know that we have to get with the times."

Linda Villarosa [] runs the journalism program at City College in Harlem and writes frequently about health issues. She attended the AIDS Vaccine conference in Barcelona as a journalism fellow. Follow her Twitter @lindavillarosa.