New vaccine offers 'stronger protection' against tuberculosis, leprosy

Scientists have discovered a new vaccine for tuberculosis and leprosy that could provide considerably stronger defense against both the diseases than the existing ones.

The currently available century-old vaccine Bacille Calmette-Guerin, or BCG, provided only partial protection against both tuberculosis and leprosy, so a more potent vaccine was needed to combat both diseases. The researchers found that rBCG30, a recombinant variant of BCG that over expressed a highly abundant 30 kDa protein of the tuberculosis bacterium known as Antigen 85B, was superior to BCG in protecting against tuberculosis in animal models, and also cross-protects against leprosy.

In addition, they found that boosting rBCG30 with the Antigen 85B protein, a protein also expressed by the leprosy bacillus, provided considerably stronger protection against leprosy. A Phase 1 human trial for rBCG30 has proven that it was safe and significantly more effective than BCG, and it was the only candidate replacement vaccine for BCG tested thus far to satisfy both of these key clinical criteria.

However, it was conducted in an animal model of leprosy, so further study is needed to gauge the effectiveness of the rBCG30 vaccine in protecting against leprosy in humans. The study will be published in the journal Infection and Immunity.