A new candidate TB vaccine: systematic review of animal studies

Article type
Kashangura R1, Sena E2, Young T1, Garner P3
1Stellenbosch University, South Africa
2University of Edinburgh, United Kingdom
3Liverpool School of Tropical Medicine, United Kingdom
Tuberculosis (TB) kills 1.4 million people every year, so an effective vaccine could have a major impact on global health. A new vaccine is currently being tested in South Africa.

As part of an evaluation of what evidence of benefit we currently have in published literature, we are carrying out a systematic review of its safety and efficacy through animal studies. We also want to test whether cumulative meta-analysis could help in evaluating animal studies prior to testing in humans.

Systematic review of animal studies evaluating modified vaccinia virus (MVA85A) vaccine to boost Bacillus Calmette-Guérin (BCG) the only accredited vaccine against tuberculosis. Outcomes were, after TB challenge: animals reaching a humane endpoint; presence of lung pathology; and bacterial loads in the lungs. We searched MEDLINE, EMBASE, Web of Science, and Biosis to January 2014.The search strategy combined MVA85A OR “modified vaccinia virus Ankara” OR Ag85A OR “Antigen 85A” ti, ab, kw AND tuberculosis or TB OR BCG ti, ab, kw. We checked references of existing trials.

We found six trials that met our inclusion criteria, five by electronic search, and one additional study by consultation with experts. The quality of the studies is currently being assessed and outcomes included in a meta-analysis that will be ready by the Colloquium.

Based on the preliminary analysis conducted at the time of writing, systematic review and cumulative meta-analysis should be used in animal research and can help provide signals to researchers and the public about the state of evidence in animal studies prior to testing in humans. Cochrane Review Groups could consider the strategic opportunities for developing collaborative links with the emerging speciality of animal evidence synthesis.