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

Area of Science:

• Immunology
• Vaccinology
• Public Health

Background:

• The Bacille-Calmette-Guérin (BCG) vaccine is effective in preventing severe infant tuberculosis (TB) but offers limited protection against adult pulmonary TB reactivation.
• Infant TB immunopathology involves lung granulomas and dissemination, contrasting with adult TB, which is often contained until immune decline.
• Global TB burden disproportionately affects countries in the global south, while high-income nations like Sweden have low incidence and limited general BCG vaccination.

Purpose of the Study:

• To review the current landscape of tuberculosis vaccines.
• To highlight the limitations of the existing BCG vaccine in adults.
• To discuss the development of novel TB vaccines for all age groups.

Main Methods:

• A comprehensive literature review was performed.
• Databases searched included PubMed, Google Scholar, and World Health Organization reports.
• The review period was from January 1st to February 28th, 2025.

Main Results:

• Cellular immunity, both innate and acquired, is key to TB protection.
• Two live attenuated vaccines are in Phase III clinical trials for infants.
• Novel TB vaccines are primarily under development for adolescents and adults.

Conclusions:

• Novel vaccines, coupled with rapid diagnostics and short treatment regimens, are essential for global tuberculosis control.
• Addressing TB requires tailored strategies for different age groups and varying disease incidence.
• Continued research and development of TB vaccines are critical to mitigate the global health threat.