An international team led by DMS infectious disease expert Dr. C. Fordham von Reyn, professor of medicine, found that the new booster, a killed vaccine, enhanced the TB immunity of HIV patients. Their weakened immune systems make the current TB vaccine, which is a live vaccine, more risky.
In most countries where TB is widespread, children generally receive a vaccine made from live Mycobacterium bovis, Bacille Calmette-Guerin (BCG) that has been used to reduce the risk of TB for more than half century. Despite the widespread use of BCG, TB has been growing dramatically in the world, fueled by the increased susceptibility of HIV-infected people to TB.
TB remains the largest cause of death worldwide from any single infectious disease, according to the National Institute of Allergy and Infectious Diseases, which calls it "the major attributable cause of death" in HIV/AIDS patients.
"Since there is no evidence that the current BCG vaccine protects patients with HIV against TB, we have been working on a new strategy to immunize persons with HIV against TB, safely and effectively," said von Reyn.
In a "back to the future" approach, the investigators revived a strategy used successfully prior to BCG: administration of killed vaccines against TB. The DMS-led team dusted off the concept to employ a multiple dose series of a contemporary killed mycobacterial vaccine to prevent TB in a particularly vulnerable and ever growing group of patients.
The study was done in Finland where BCG vaccine is routinely administered at birth. A cohort of 39 HIV patients, mainly men, were divided into two groups to receive a five-dose course of the killed vaccine, Mycobacterium vaccae, or a control vaccine
Contact: Andy Nordhoff
Dartmouth Medical School