Setback for AIDS-Vaccine Research

A man receives care at the AIDS Healthcare Foundation pharmacy in April 2013 in California. (Kevork Djansezian/Getty Images)
A man receives care at the AIDS Healthcare Foundation pharmacy in April 2013 in California. (Kevork Djansezian/Getty Images)

(The Root) — First do no harm. That's the golden rule of medicine. But a new analysis of a trio of AIDS-vaccine trials shows that's exactly what happened in two of the three studies.

In trials conducted across four continents with a combined total of more than 6,000 participants, vaccines using a flulike virus that were designed to protect men and women from contracting HIV actually made it 33 percent more likely that those men and women would get infected. The analysis was presented on Thursday at AIDS Vaccine 2013, an international conference in Barcelona, Spain. Though this data isn't brand-new — and, in fact, each of these studies was stopped once scientists realized that the vaccines didn't work — this was the first public glimpse of the unpublished data pooled from all three studies.

The news was particularly disappointing, since an AIDS vaccine would be a game changer. Worldwide, 2.3 million people become newly infected with the virus each year, and Africa continues to be the world's most affected region. In the United States, blacks make up nearly half of all new HIV infections, and AIDS remains one of the top killers (pdf) of both black men and women.


Although new infections have dropped by one-third over the past decade because of improved prevention methods, even in the United States only 25 percent of people with HIV are receiving treatment to the point where the virus is "undetectable" in the bloodstream. This leaves them vulnerable to getting sick and spreading the disease to others.  

There was some good news in the report: When teased out, one of those three trials — the one focused on the U.S. only — showed no increased risk to those who received the vaccine. The studies were looked at together because each used a form of adenovirus, a cousin of the common cold. If the U.S. trial is taken out of the mix, the elevated risk of infection in the other two studies combined soars to 41 percent.

The U.S. trial targeted gay men and transgender women, and only 16 percent of participants were African American. It is still difficult to recruit blacks — LGBT or straight — into any kind of medical research. Well-documented distrust of the health care system and a false belief that the government infected communities of color with HIV kept African Americans from mobilizing early in the AIDS epidemic. And it keeps many of us from taking part in AIDS-vaccine trials.

"It's better than in the past, since so many of us now know someone with HIV and want to help," says Steve Wakefield, director of community education for the HIV Trials Network. "There's also a sense that people who participate in research are now heroes, whereas in the past they were seen as crazy. But it remains a challenge."


Today's announcement added a wrinkle to the quest to find a vaccine that stops HIV — a frustrating 30-year journey characterized by one step forward, two steps back. Those involved in the studies took pains to look for the silver lining. "There is no such thing as a failed trial," said Dr. Glenda Gray, the chair of the research conducted in South Africa. She struggled to control her emotions as she discussed the results of her study at the press event today.

"These trials tell us very important things, and the findings help us move forward," she added. "That said, every participant, whether on the placebo or the vaccine, is precious to us."


Researchers stress that AIDS vaccines — including the ones analyzed in the new report — do not cause infection, a common misconception. Vaccine trials work this way: Scientists recruit participants to a trial and divide them into two groups. One set of people receives an experimental injection that may protect against HIV, while another group is given a placebo, or "mock," vaccine.

Researchers then compare the two groups over time. Everyone in the trial receives a standard package of prevention — including safe-sex counseling, condoms and treatment for other sexually transmitted infections — to minimize the risk of contracting HIV.


The bottom line is that participants who contracted HIV during the trails got infected through unsafe sex, not as a result of the vaccine. 

"The takeaway is that we cannot rely on people to change their behavior; they're going to have sex," said Wakefield. "It's going to take a vaccine to protect future generations from this epidemic."


The new analysis and the painful discussions that have followed help untangle what happened, though the "why" remains unclear. The narrative goes like this:

* The first of the studies, STEP, was designed to test a vaccine in 3,000 men who have sex with men and heterosexual women in the United States, Latin America, the Caribbean and Australia. By 2007 the research was ground to a halt when it not only was ineffective but also increased the risk of contracting HIV.


* HVTN 503, known as Phambili, was carried out in South Africa with 801 men and women, using the same vaccine as STEP. Once researchers heard about the failed STEP study, they abruptly stopped their research. Follow-up showed greater risk of HIV to those receiving the vaccine.

* The final trial in this series was conducted with 2,500 gay and transgender participants across the United States. It used a vaccine similar to the previous two but included additional precautions to avoid problems in the other trials. Still, in April of this year that study was also stopped. 


Those in the field point toward other, more promising research. Last month a study showed that a vaccine "cleared" HIV in monkeys that had been infected with the virus. In science-speak, "cleared" means cured. Before that, good news came four years ago, when an AIDS vaccine studied in Thailand reduced the risk of HIV infection in people for the first time in history. The results didn't prove strong enough to get a vaccine in the pipeline, so in the future, scientists will work to improve upon the results.

They have their eye on a clinical study in Africa and Thailand known as P5 that kicks off in a few years and builds on the successes and setbacks of the work that came before. It may be a while.


"HIV is a tricky disease to make a vaccine for," sums up William Snow, director of the Global HIV Vaccine Enterprise. "That's why it's taken us 30 years to get this far."

Linda Villarosa runs the journalism program at the City College of New York and is a frequent contributor to The Root. She is reporting from the international AIDS-vaccine conference in Barcelona as a journalism fellow. 

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