BCG vaccination prevents child TB and is cost-effective worldwide

Tuberculosis remains a threat to children in many parts of the world, and Bacille Calmette-Guérin (BCG) is the most widely used vaccine to protect them. Despite that widespread use, multi-country analyses of BCG's value are outdated and have not fully accounted for long-term consequences in survivors of childhood tuberculosis. A further practical question has been how large vaccine safety stocks should be to prevent shortages without wasting resources. To address these gaps, Peter J. Dodd and colleagues conducted a global, country-level analysis focused on the 110 countries that in 2023 used universal neonatal BCG vaccination. They compared the current policy of vaccinating children aged 0–4 years with a counterfactual scenario in which no BCG vaccine was used. Importantly, their decision tree model included post-tuberculosis sequelae—health problems that can persist after surviving an infection—and evaluated costs and health outcomes from a health system perspective. The team also developed a rationale for the optimal size of safety stocks, balancing uncertainty in vaccine demand with economic considerations.

The researchers used a decision tree model to tally both health benefits and costs of continuing universal neonatal BCG versus stopping it, across the 110 countries using the vaccine. They judged cost-effectiveness against a threshold set at 30% of per capita gross domestic product and considered only health system costs. Their results showed that universal neonatal BCG vaccination in 2023 likely prevented about 742,000 tuberculosis episodes (95% uncertainty interval: 541,000 to 991,000) and roughly 192,000 tuberculosis deaths (95% UI: 138,000 to 264,000) globally. Of these prevented events, an estimated 49,000 episodes (95% UI: 32,300 to 72,100) and 30,000 deaths (95% UI: 19,600 to 45,100) were cases of tuberculous meningitis. On cost-effectiveness, BCG was supported in the majority of countries using it (75 of 110) and in every country with estimated tuberculosis incidence above 42 per 100,000 per year. The median incremental cost-effectiveness ratio was $276 per disability-adjusted life-year averted (IQR: $84 to $1,514). For vaccine supply planning, the median optimal safety stock—assuming a 10% uncertainty in demand—was 11% of expected demand (IQR: 7% to 17%).

These findings underline that continuing universal neonatal BCG vaccination prevents substantial illness and death among children worldwide and is an economically reasonable choice in most countries that currently follow this policy. By explicitly including post-tuberculosis sequelae, the analysis by Peter J. Dodd and collaborators captures a fuller picture of the long-term benefits of vaccination, which can strengthen the argument for sustained programs and funding. The clear threshold-based results—showing cost-effectiveness in all countries with incidence above 42 per 100,000—give policymakers a simple benchmark to guide decisions. The study also provides practical guidance on vaccine stockpiles: modest safety stocks, around the low tens of percent of expected demand, can balance the risks of shortages against the costs of overstocking. Funded by UK EPSRC & DHSC, the work supplies evidence that can help health ministries and international partners plan vaccination programs and procurement more confidently without waiting for new clinical trials.