AIDS Vaccine 2012 Opens in Boston

It’s been almost three years to the day that the surprisingly upbeat results from the RV144 trial in Thailand, which demonstrated the first and thus far only evidence of vaccine-induced protection, hit the newsstands and airwaves and re-energized the field. Yet a series of ambitious efforts set forth not long after to try and improve upon the modest 31.2% efficacy seen in the trial of 16,000 at-risk men and women from Thailand—and perhaps see a candidate to market—have been tempered by the realities of the ground war.

Ask Jerome Kim.

Kim, the deputy director of science and chief of the Department of Molecular Virology and Pathogenesis at the U.S. Military HIV Research Program (MHRP), was understandably frustrated about the status of the two planned efficacy trials—one in high-risk men who have sex with men (MSM) in Thailand and a second among high-risk heterosexual men and women in South Africa—that trial organizers hoped would begin by late 2012 but likely won’t start until 2014 at the earliest. “So this is a little depressing,” said Kim, during a satellite session that preceded the opening of the AIDS Vaccine 2012 conference. The three-hour session, devoted to HIV vaccine efficacy trials, laid out some of the many challenges, ranging from money to infrastructure, that have impeded efforts to get large trials off the ground. 

The follow up efficacy trial in Thailand is especially concerning. Kim said trial organizers of the study has  struggled to find a vaccine developer willing to manufacture the protein boost and to shepherd it through the regulatory approval process should it be considered suitable for licensure. Kim says it will take 24-36 months to manufacture the protein boost, meaning that the earliest the trials could start would be 2015.  Meanwhile, Novartis has contracted to make the protein boost for the South Africa efficacy trial, and trial sponsors are hoping for a start date in late 2014. 

The MHRP was one of the project leaders of the RV144 trial and it is now an integral player in the Pox-Protein-Public-Private-Partnership, or P5—formed by stakeholders a year ago to increase the vaccine efficacy seen in the RV144 trial from 31.2% to 50%. The efficacy trial in South Africa that the P5 would like to see conducted is being designed to evaluate a prime-boost vaccine candidate in South Africa similar to the ALVAC-HIV (vCP1521) canary pox viral vector prime and the gp120 B/E AIDSVAX boost tested in 16,000 at-risk men and women in the RV144 trial in Thailand. The new candidate consists of the highly attenuated vaccinia virus NYVAC—a cousin to ALVAC—as the prime coupled with a gp120 protein boost formulated with the MF59 adjuvant. The P5 also planned an efficacy trial in a MSM cohort in Thailand to improve upon the RV144 result with a slightly modified candidate—an ALVAC prime coupled with a gp120 boost formulated with an MF59 adjuvant. 

This slow pace of clinical trials was touched on later that day by Bill Snow, when he delivered an unusually blunt address to 1,000 attendees at the opening ceremonies of AIDS Vaccine 2012 on Sunday evening. Snow was recently appointed executive director of the Global HIV Vaccine Enterprise, which organizes the scientific meeting. “My focus has always been, quite frankly, how to get to a vaccine,” said Snow. “Tonight, quite frankly, I’m taking you to task.”

Snow, a longtime AIDS advocate who was appointed director of the Enterprise six months ago, couldn’t help sounding a wee bit scolding as he urged the field to be better advocates and to close the yawning gaps between efficacy trials. “We’re short on resources and long on little tweaks,” he said.

He said the field must remake the argument for an HIV vaccine in the context of other HIV prevention strategies, such as ARV-based methods. “ARVs could end AIDS, a vaccine could end AIDS, but ARVs and a vaccine together can end AIDS,” said Snow.

Indeed, the theme of the conference, “New Minds, New Ideas, New Approaches,” will open its first full morning of talks on Monday with a quartet of cross-pollinating lectures that showcase not only vaccines but microbicides, and two ARV-based strategies—the administration of antiretrovirals prior to exposure to prevent HIV, and earlier treatment for HIV-infected individuals to prevent transmission—and how they might be used in combination to bring an end to AIDS. 

Even the choice of opening night speaker Paul Farmer, the chair of the department of Global Health and Social Medicine at Harvard Medical School and the founder of the international nonprofit Partners in Health that is well known for its work in Haiti, was somewhat offbeat, as Farmer is not a vaccine scientist. —Regina McEnery