“When they ask me is the glass half empty or half full [in regards to AIDS cure research], I say… we have a glass,” Carl Dieffenbach, PhD, told an audience at the 2012 International AIDS Conference in Washington on Sunday.
Dieffenbach, director of the Division of AIDS at the National Institute of Allergy and Infectious Diseases (NIAID) at the National Institutes of Health (NIH), first highlighted the findings of the 16,000-participant Thai HIV vaccine trial, released in an October 2009 article in the New England Journal of Medicine. The study showed that those who received the vaccine were about 31 percent less likely to be infected than those who did not. “We must as a community follow up on the RV144 trial result to confirm or deny that finding, and test a number of hypotheses to advance broadly neutralizing antibodies into proof of concept,” Dieffenbach said. The greater the concentration of antibodies, the lower the rate of infection, he said.
He moved on to discuss a cure, which he defined as permanent remission in the absence of the need for therapy, where an HIV infected person could stop antiretroviral therapy and not have ongoing viral replication at a level that causes disease or allows that person to transmit to others. A “sterilizing cure” would eradicate the virus, and a “functional cure” would permanently suppress the virus without elimination from the body.
The main obstacle to cure research is that HIV hides from the immune system and forms a latent reservoir protected from drug therapy, he said. Research targeting these residual reservoirs is one of the foci of the Martin Delaney Collaboratory: Towards an HIV-1 Cure program at NIH – launched in memory of the founding director of Project Inform Martin Delaney, the “founder of expanded access to therapy” who in his later years urged continued research for a cure.
“We have the targets,” for cure research, which include latently infected resting CD4 cells and “CCR5” (a protein on the surface of white blood cells), “… now we must maintain the momentum,” Dieffenbach said.
Francis Collins, MD, PhD, head of the National Institutes of Health (NIH), also gave remarks, during which he showed a map of countries where NIH has research investments and nearly the entire globe was covered. Ten percent of the NIH budget is dedicated to HIV/AIDS research.
Anthony Fauci, MD, head of NIAID, discussed HIV prevention briefly, noting the fact that prevention is a multidimensional effort. Combination prevention is needed to address the 2.5 million new HIV infections we still see every year globally, and the 1.5 million deaths. “Prevention looms very large,” Fauci said.
Reinforcing the urgency of Dieffenbach’s message, Fauci said the two major challenges that lie ahead in the fight against AIDS are finding a vaccine and a cure.