As our feature story this week makes clear, the fight against HIV/AIDS is far from over. But researchers from the University of Washington and the Fred Hutchinson Cancer Research Center have made significant progress developing a vaccine for the virus, and the Gates Foundation has spent more than $2.2 billion funding the science.
Here's what "Prime-boost" means in plain English, courtesy of UW:
This method uses two vaccine components -- a relatively harmless virus that delivers HIV proteins and primes the immune system, followed by booster shots of the HIV proteins themselves. This one-two punch approach activates both antibody and cell-mediated immune responses...Earlier this week, Hu was awarded a $6.7 million grant from the Gates Foundation, allowing him to join their Collaboration for AIDS Vaccine Discovery. Launched in 2006, the Collaboration is a group effort that has included more than 500 investigators from 94 institutions in 19 countries.
...The goal of [Hu's] study is to build upon the success of the prime-boost strategy and to explore vaccine designs that may generate protective antibodies targeting the part of the virus it uses to bind to immune cells -- the part widely considered the Achilles heel of the virus. Hu's lab has previously shown that the removal of a specific glycan molecule on the envelope protein used by the virus to enter the host cell resulted in an enhanced ability of the mutant protein to induce neutralizing antibodies.
Despite the specificity of their name, the Fred Hutchinson Cancer Research Center also specializes in HIV/AIDS research. The Hutch leads the HIV vaccine trials network (HVTN), a global network currently testing 12 different prospective vaccines.
Dr. Jim Kublin, executive director of the HVTN, says some "very exciting" research will be published in the coming weeks in the New England Journal of Medicine regarding "correlates" for HIV protection. In layman's terms, a correlate is like a signpost that points scientists toward what works about a particular vaccine and why.
"Evidence that there's a biological marker for that potential protection is a major milestone for the field," Kublin says. "We can now use that as one among several benchmarks to measure other vaccines, and develop them to make them more effective. That's the biggest news out of the field in the past couple months."
The study was conducted in Thailand (a continuation of the RV144 Trials), and the statistical analysis done at the Hutch. Kublin says his group is "conducting more clinical trials [for HIV vaccines] than any other group in the world right now."
Another highlight is research by doctors Julie Overbaugh and Catherine Blish. They found that two mutations in one strain of HIV-1 could make the virus vulnerable to attack by the body's immune system. According to the Hutch, "these findings could form the foundation for new vaccines that could help the body to fight off HIV."
The bad news is that, despite all the progress, about 2.3 million people still become newly infected with HIV every year. (Our feature this week focused on whether a form of birth control popular in Africa is contributing to the spread of HIV.) The good news is that anti-retroviral drugs and other forms of treatment have turned a disease that used to be 100 percent fatal into one for which average life expectancy exceeds 20 years. That's progress.