The HIV Vaccine Trials Network (HVTN) and Merck & Co., Inc. announced last month that they have begun a collaborative study to test a promising new vaccine to prevent HIV/AIDS. The trial will be conducted at both Merck and HVTN clinical trial sites in North and South America, the Caribbean and Australia.
The vaccine to be tested in the study has generated strong and durable immune responses against HIV in early human trials. This collaboration could accelerate HIV-vaccine development work by guiding scientific decisions for future HIV-vaccine trials.
The study is a collaboration of Merck, the HVTN and the National Institute of Allergy and Infectious Diseases, which funds and supports the HVTN. It combines the clinical-trials experience and global capacity of the HVTN with the strength of Merck's vaccine research efforts and clinical trials expertise.
The trial is known as a "proof-of-concept" study because it enables researchers to test the concept that the vaccine candidate prevents HIV infection, or results in lower HIV levels in the blood of those who become infected with HIV. If the concept is proven — that is, if data generated by the study show that the vaccine candidate provides some protection against HIV, or delays or diminishes the course of HIV infection — this information will guide future research.
"This proof-of-concept study will involve the cooperation of scientists, government officials, and community leaders from many different countries, underscoring the global response necessary to move the science forward," said Dr. Larry Corey, HVTN principal investigator and head of the center's Infectious Diseases program.
This vaccine candidate is designed to generate a cellular immune response, as opposed to the antibody response typical of most vaccines in use today. The trial is expected to provide vital data about the ability of this vaccine approach to either prevent infection with HIV, and/or to maintain a lower average level of virus in the body (viral load) compared with placebo in individuals who may become infected with HIV during the course of the study. The study will also evaluate whether the vaccine is generally well tolerated by study participants.
The human toll
The Joint United Nations Programme on AIDS (UNAIDS) has reported that a record 3.1 million people died of AIDS in 2004, the highest number for any year since the epidemic began. As with other infectious diseases, development of a vaccine is recognized as the best long-term hope to end the AIDS pandemic. Vaccines are a critical part of an integrated strategy to fight HIV infection, which also includes treatment and prevention.
The HVTN comprises more than 25 research institutions worldwide, coordinated from its headquarters at Fred Hutchinson Cancer Research Center in Seattle.