The Paediatric BCG Vaccine Century: From Historical Success to Future Innovations.

Aim: The tuberculosis (TB) vaccine, Bacille-Calmette-Guérin (BCG), protects infants against severe forms of primary TB. Yet, it does not protect against pulmonary reactivation TB in adults.

Methods: A literature review was conducted between 1st January and 28th February 2025 using PubMed, Google Scholar and reports of the World Health Organization.

Results: Protection against TB includes innate and acquired cellular immunity and infants are more susceptible due to immature immunity. Immunopathology of infant TB is characterised by formation of small granulomas in the lung often followed by dissemination to other organs. Infection in adults is frequently contained until immunity is weakened and TB disease develops. Novel vaccines are being developed mostly for adolescents and adults, but two live attenuated vaccines are currently assessed in infants in Phase III clinical trials. Globally, TB remains a major health threat and countries of the global south bear the major TB burden. Today, Sweden, similar to other high-income countries, has a low incidence. General vaccination has therefore been terminated and targeted BCG vaccination is offered to infants at higher risk.

Conclusion: Together with short-treatment and rapid diagnosis, novel vaccines profoundly contribute to the fight against TB in all age groups.