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.