In a press release by Dartmouth Medical School on January 29th, researchers reported on the successful creation of a vaccine for HIV-associated tuberculosis. Immunization with the vaccine was found to reduce the rate of tuberculosis (TB) infection by 39 percent.

The study, dubbed the DarDar Health Study, was a 7-year collaboration among groups in the United States, Zambia, Finland, and Tanzania.

Currently, TB is the leading cause of death among HIV-positive individuals in developing countries, and is responsible for approximately half of all the deaths worldwide of people with AIDS.

Almost immediately after contracting HIV, all patients are at an increased risk for TB infection. The CDC estimates that one third of HIV patients are also coinfected with TB.

Therefore, the invention of a vaccine against HIV-associated tuberculosis has been a priority, and the successful results of this study represent a significant achievement in the worldwide effort to prevent tuberculosis in HIV-infected individuals.

The novel vaccine used, Mycobacterium vaccae (MV), is known as an inactivated, whole-cell vaccine. Vaccines of this type are comprised of entire MV cells that have been killed prior to injection.

Researchers treated 2,000 HIV-positive patients in Tanzania with either the vaccine or placebo, all of whom had received the current TB vaccine, Bacille Calmette-Guerin (BCG), during childhood.

Along with increased protection against contracting TB, patients treated with the experimental vaccine experienced no negative effects on HIV viral load or CD4 cell count (white blood cell count).

The next steps are to establish a manufacturing scheme to provide enough of the vaccine for additional trials and eventually, clinical use. Experts expect the production and distribution of the vaccine to be relatively inexpensive.

For more information on the study or its results, please see the related AIDS Beacon article, the AIDS Journal research article (abstract) or the Dartmouth press release. More information on the HIV/tuberculosis relationship can be found at the CDC Web site.