The existing vaccine

The BCG vaccine was developed in 1921. No new vaccine has appeared since.

For reasons which may be associated with existing bacilli found in local soils which are too similar to the tuberculosis bacilli, the existing vaccine simply doesn't work reliably in the tropics. Despite this (as sadly as with TB drug research) no real effort has been made regarding new vaccines until quite recently.

The prospect of a new vaccine

The last we've heard, there may be a new vaccine available by 2017 (though projected dates do seem to slip from time to time because of inherent difficulties in development).

From the perspective of a manufacturer, however, a newly patented vaccine could be a highly profitable product, particularly if the incidence of TB rises in the developed world.

From the perspective of the developing world, however, where latent infection runs so high, the prospect is largely inconsequential for at least a generation. 4 out of 5 people in Africa are estimated to be latently infected with TB. No vaccine in the world can protect them from an infection they already have.

The same applies to the other one-and-a-half billlion people worldwide who are recognised as being latently infected.