Tuberculosis has been killing people for centuries and the prospect of a vaccine to stop this has eluded scientists for years. In 2012, the Bill and Melinda Gates Foundation invested an initial USD 220 million in tuberculosis vaccine development through AERAS; one of the candidate vaccines that advanced, known as MVA85A, was developed as an add-on to the existing BCG vaccine and was evaluated in a number of trials.
In this Cochrane Review, the review authors summarise six studies related to the four randomised trials that evaluated the efficacy of the vaccine. All included trials were conducted in Africa and mostly in children, including the largest trial in 2797 children. All the trials included the authors from Oxford who led the development of the vaccine in the laboratory.,
The evaluation of these phase 2 trials shows that, MVA85A added to the BCG compared to the BCG alone probably has no effect on the risk of developing tuberculosis. While there were more local skin reactions in people vaccinated with MVA85A, the vaccine did not cause any life-threatening side effects.
Lead author Rufaro Kashangura, from Nhlangano Health Centre in Swaziland, stated “Whilst the review will come as no surprise to specialists in the field as the results echo those of the large trials of effects - which most saw as the death of the vaccine - what the review does is document the huge amount of effort put into the testing of this vaccine, with methodological lessons for other trials.”
Issues surrounding the transition of this vaccine to human trials were also highlighted in a systematic review of animals published in 2015 by several of the same authors on this current Cochrane Review.
This Cochrane Review was co-ordinated by the Cochrane Infectious Diseases Group (CIDG), which has its editorial base at LSTM. The CIDG has been in operation since 1994 and consists of over 600 authors from 52 countries and is supported by UK aid from the UK Government for the benefit of low- and middle-income countries (project number 300342-104).
Kashangura R, Jullien S, Garner P, Johnson S. MVA85A vaccine to enhance BCG for preventing tuberculosis. Cochrane Database of Systematic Reviews 2019, Issue 4. Art. No.: CD012915. DOI: https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD012915.pub2/full
This news article was first published on the LSTM website.