Prospects for new tuberculosis vaccines

Abstract

The world urgently requires a new vaccine to combat the problem of tuberculosis (TB). The failure of BCG vaccine the emergence of extensively drug-resistant TB and the increasing global TB-related mortality has emphasised the urgent need to develop more effective TB vaccines to combat this scourge. The development of new genetic technology and the sequencing of the Mycobacterium tuberculosis genome in the late nineties have made the rational development of new TB vaccines a reality. The ideal TB vaccine should be affordable especially in the poorest countries of the world where it is most needed and should be more cost-effective than BCG vaccine. It should be easily administered at or soon after birth and be safe immunogenic and effective at all ages and in all populations. It is unlikely that a single new vaccine candidate will meet all or even most of these requirements and it is likely that more than one new vaccine will be needed. TB is a leading opportunistic infection in HIV-positive persons. New TB vaccines would therefore have to be safe immunogenic and effective in this at-risk population as well. Recently the WHO has recommended that children who are known to be HIV positive even if they are asymptomatic should not be given BCG vaccine because of the high risk of possibly developing disseminated BCG disease. (excerpt)