VACCINATION AGAINST TUBERCULOSIS BY DNA INJECTION

There are 3 million deaths per annum worldwide due to tuberculosis, an d AIDS is compounding the problem. A better vaccine than the live myco bacterium currently in use, bacillus Calmette-Guerin (BCG), is needed. When mice were injected with plasmid DNA encoding a single mycobacter ial antigen (65-kDa heat shock protein, hsp65) they made specific cell ular and humoral responses to the protein and became immune to subsequ ent challenge with Mycobacterium tuberculosis. Protection was equivale nt to that obtained by vaccinating with live BCG, whereas immunizing w ith the protein was ineffective. Protection was also obtained with DNA encoding another mycobacterial antigen (36-kDa proline-rich antigen). These results suggest that DNA vaccination might yield improved vacci nes to replace BCG.