FORT COLLINS, Colo.--Researchers at Colorado State University report that two new vaccines show promise in preventing tuberculosis in animals.
While not currently as effective as the BCG vaccine, developed in the 1950s and commonly used in Europe, with further development the new vaccines may offer long-term immunity, according to a report by a Colorado State team published in the June issue of the journal Infection and Immunity.
The vaccines have the potential to supplement BCG, believed to lose effectiveness over a period of time, and unlike BCG do not produce positive skin tests for TB in vaccinated individuals.
Ian Orme, professor of microbiology at Colorado State and head of the 10-person team that evaluated the substances, said the vaccines, one developed at Colorado State and the other by the Merck Co., use entirely different approaches to fight tuberculosis.
BCG isn't used in the United States because until recently, U.S. medical authorities expected TB to be eradicated early in the next century. Instead, the disease has become the leading bacterial killer in the world, causing 10 million new cases and 3 million deaths each year.
Since 1992 Orme and his colleagues have not only pursued their own basic research interests, but with support from a grant from the National Institutes of Health have operated a TB vaccine screening program that has examined dozens of experimental vaccines, including the two reported on this month.
The vaccines described in the Infection and Immunity article work in a different fashion than BCG, which triggers an immune response using weakened bovine tuberculosis bacilli.
The Colorado State vaccine, developed over the past several years by a team led by Orme, uses specific proteins isolated from the tuberculosis bacterium. When mixed with interleukin-2, a protein known to boost the immune system, and added to a carrier called an adjuvant that also helps boost immunity,
Contact: David Weymiller
Colorado State University