In June 2023 Wellcome and the Bill and Melinda Gates Foundation announced funding to advance a tuberculosis (TB) vaccine candidate through a Phase III clinical trial. If this vaccine succeeds in trial, it could become the first new vaccine against pulmonary TB in over 100 years. The trial will cost an estimated $550 million, divided between Wellcome ($150 million) and the Gates Foundation (around $400 million)
TB continues to cause widespread illness and death across the globe, with the greatest burden of disease in low- and middle-income countries. The Gates Foundation states that “those at highest risk are often living in poverty, with poor living and working conditions and undernutrition”. Although it is curable, it remains one of the deadliest infectious diseases, says Julia Gillard, chair of the Board of Governors at Wellcome.
“The development of an affordable, accessible vaccine for adults and adolescents would be game-changing in turning the tide against TB.”
She emphasises the importance of philanthropy as a “catalyst to progress”.
“Sustainable progress against TB and wider disease threats will depend on global collaboration, financial backing, and political will.”
Limited protection and treatment
The current vaccine against TB is bacille Calmette-Guérin (BCG), first administered in 1921. Although effective in protecting young patients against systemic forms of TB, it is less effective for adolescents and adults. Alongside the obvious need for innovation in prevention, access to treatment is described by Wellcome as a “major challenge” for patients in low- and middle-income countries. This is due to several reasons such as “production monopolies” and “high prices”.
The vaccine candidate, M72/AS01E (M72) offers “new hope” for a “TB-free future”, says Head of Public Engagement at Africa Health Research Institute, Nomathamsanqa Majozi.
“In the area where I live and work, more than half of all people have had, or will have, TB at some point in their lives. The consequences are devastating, both at a personal and a community level.”
Bill Gates agrees that with “cases and deaths on the rise”, the need for “new tools has never been more urgent”.
“Greater investment in safe and effective TB vaccines alongside a suite of new diagnostics and treatments could transform TB care for millions of people, saving lives and lowering the burden of this devastating and costly disease.”
M72 is one of 17 TB vaccine candidates in the pipeline, developed by GSK in partnership with Aeras and IAVI, with contributions from the Gates Foundation. In Phase IIb trials it showed “unprecedented” efficacy in reducing pulmonary TB in adults with latent TB infection: around 50%. The Gates Foundation suggests that over 25 a vaccine with this level of efficacy or greater could prevent up to 76 million new TB cases and 8.5 million deaths. This would save $41.5 billion in TB-related catastrophic household costs, says WHO.
M72 contains the M72 recombinant fusion protein, derived from two Mycobacterium tuberculosis antigens, and combined with the GSK proprietary Adjuvant System AS01E. The Phase III trial is due to begin in 2024 and is set to enrol around 26,000 people at over 50 trial sites in Africa and South-East Asia. It is sponsored by the Gates Medical Research Institute and will be carried out in collaboration with a consortium of clinical investigators.
Turning the TB tide
WHO Director-General Dr Tedros Adhanom Ghebreyesus believes that the world can make a change through sustained political and financial action, calling for a new vaccine to “reduce disease transmission and avoidable death”. Cheryl Moore, Chief Research Programmes Officer at Wellcome, emphasised the organisation’s commitment to “catalysing critical research and development”. She identified the need for “partnerships and political will” to enact “sustainable change” for those who need it most.
However, Dr Alexander Pym, Director of Infectious Disease at Wellcome, warns that although M72 could be a “valuable addition to our toolkit”, we need “significant global investment” to achieve a “TB-free world”.
How do you think we can encourage greater investment and interest from the global community? For an expert opinion, check out our interview with Dr Mark Feinberg of IAVI here.
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