Gates Foundation TB shot to undergo $550m late-stage test

A Bill & Melinda Gates Foundation vaccine against tuberculosis, long one of the world’s deadliest infections, will undergo a $550 million final-stage trial to determine whether it can replace a century-old shot with limited effectiveness.

The Gates Foundation will provide $400 million to study the shot along with as much as $150 million from the UK-based Wellcome Trust, the health charities said Wednesday in a statement. Originally shepherded by vaccine giant GSK Plc, studies of the shot are now led the Gates Medical Research Institute.

About a quarter of the world’s population is infected with TB, and 1.6 million people died of the disease in 2021, the vast majority of them in low- and middle-income countries. Limitations of the current shot, called BCG, have led researchers to study a range of options for improvement, looking for ways to give better protection across a broad population.

“A TB vaccine would really be a game-changer, and essential for global control.” Alexander Pym, director of infectious disease for Wellcome, said on a call with reporters.

Among the world’s most widely used vaccines, BCG is safe and gives good protection against the most severe forms of TB, such as cases of brain and spinal cord infections in young children. However, it’s less effective in preventing TB lung infections in adults, and doesn’t stop the disease from spreading.

Only 5% to 10% of infected people develop the disease, and there are huge numbers of latent cases that can become more serious; people with HIV are at especially high risk. Research published in 2018 showed the Gates vaccine was 50% effective at preventing disease in the lungs for adults with latent infections.

Hopes are high for the experimental vaccine after an Oxford-developed shot that was the most advanced candidate in 90 years failed to show efficacy in a 2013 trial in South Africa. Gates helped fund GSK’s mid-stage research, which worked with the International AIDS Vaccine Initiative to test the shot in latent cases.

GSK licensed the candidate to the Gates Medical Research Institute in 2020. The shots still use the drugmaker’s AS01E adjuvant, which helps boost the body’s immune response.

The late-stage trial will begin in early 2024 and take an estimated four to six years, Trevor Mundel, president of global health for the Gates Foundation, told reporters. Both Gates and Wellcome want the vaccine to be affordable and available in sufficient quantities to meet global treatment needs, he said.

A World Health Organisation-backed group is working on yet another vaccine for TB that uses the mRNA technology pioneered in Covid-19 shots from Moderna Inc. and the partnership of Pfizer and BioNtech SE.

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