New TB vaccines could produce substantial health and economic benefits in coming decades
Modelling suggests that an effective new tuberculosis vaccine could produce US$ 474 billion in health and economic benefits by 2050 and would be cost-effective in many low- and middle-income countries
- 3 February 2023
- 4 min read
- by Linda Geddes
The development and roll-out of new tuberculosis (TB) vaccines could yield health and economic benefits on a similar scale to some of the most influential health interventions in poorer countries in recent years, data suggests.
Having modelled the impact of vaccine introductions in low- and middle-income countries, researchers found that an effective new TB vaccine for adolescents and adults would be cost-effective in 73 of 105 (70%) of settings – including all those with a high TB burden – and could produce up to US$ 474 billion in economic benefits by 2050.
The scale of these benefits would be on par with some of the most influential health interventions in LMIC settings in recent years.
"While challenges remain, successful development and introduction of a new TB vaccine has potential to accelerate elimination of a disease that represents one of the greatest health threats for poor households," said Dr Allison Portnoy at the Harvard T.H. Chan School of Public Health, who led the study.
TB is one of the world's leading infectious killers. In 2021, approximately 10.6 million people fell ill with TB, and 1.6 million died from it. Although TB is curable when treated with antibiotics, drug-resistant TB is a growing problem. Meanwhile, millions of infected people are either not diagnosed or not treated, putting them at risk of dying and/or infecting others.
While the BCG vaccine is moderately effective in preventing severe forms of TB in infants and young children, it does not adequately protect adults and adolescents, who account for almost 90% of disease transmission. Developing new safe, affordable, and effective TB vaccines is considered critical for eliminating TB, yet while promising candidates exist, such as the M72/AS01E candidate vaccine, limited market incentives have delayed their development.
Economic analysis
Although previous studies have highlighted the economic impact of TB, and the potential impact new vaccines could have, the cost and cost-effectiveness of these vaccines may vary by country – and such country-specific data is needed to help vaccine developers, manufacturers, and potential purchasers decide where to focus their investments.
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To help fill this gap, Portnoy and her colleagues assessed the future costs, cost-savings, and cost-effectiveness of introducing novel TB vaccines using a range of different assumptions about vaccine price and delivery strategies, calibrated with data from 105 different LMICs.
The research, published in PLOS Medicine, found that the substantial near-term costs of introducing a new TB vaccine would be offset by future cost-savings associated with caring for people with TB, and their ability to contribute to the economy by staying healthy.
Substantial benefits
In the case of a new adolescent/adult vaccine, assuming an efficacy of 50% at preventing disease (the World Health Organization's preferred threshold for a new TB vaccine), the team estimated that it could produce between $283 billion and $474 billion in economic benefits by 2050, with these benefits concentrated in the WHO African and South-East Asian regions – areas with the highest TB burden.
The scale of these benefits would be on par with some of the most influential health interventions in LMIC settings in recent years – including universal test-and-treat strategies for HIV – Portnoy said.
For a new infant vaccine, assuming an efficacy of 80% efficacy at preventing disease, it would be cost-effective in 56 out of 105 countries (53%), including all of those with a high TB burden. It would produce economic benefits of $44.5 billion to $100 billion.
"There was greater, and more rapid, impact from an adolescent/adult vaccine over the 2028-to-2050-time horizon compared to an infant vaccine, as this vaccine is targeted to a population with the highest burden of TB, and the delay between vaccination and TB prevention impact is shorter with the adolescent/adult vaccine," Portnoy and her colleagues wrote.
"The results of these analyses can be used by global and country stakeholders to inform TB vaccine policy and introduction preparedness, as well as decision-making around future development, adoption, and implementation of novel TB vaccines," said Portnoy.
