To BCG or Not Two BCG

This editorial discusses the implications of a phase 2b clinical trial evaluating BCG revaccination for tuberculosis prevention. The authors analyze findings from Schmidt et al., which show no protective effect of BCG revaccination in adolescents against Mycobacterium tuberculosis infection, nor an increase in transient IGRA conversions, contrary to prior studies. They explore possible reasons for vaccine failure, including variability in immune response, differences in mycobacterial strains, and the challenge of developing vaccines that target appropriate T-cell antigens. The commentary emphasizes the need for next-generation tuberculosis vaccines that can elicit stronger and more targeted immune protection, especially in populations at risk.

This editorial discusses the implications of a phase 2b clinical trial evaluating BCG revaccination for tuberculosis prevention. The authors analyze findings from Schmidt et al., which show no protective effect of BCG revaccination in adolescents against Mycobacterium tuberculosis infection, nor an increase in transient IGRA conversions, contrary to prior studies. They explore possible reasons for vaccine failure, including variability in immune response, differences in mycobacterial strains, and the challenge of developing vaccines that target appropriate T-cell antigens. The commentary emphasizes the need for next-generation tuberculosis vaccines that can elicit stronger and more targeted immune protection, especially in populations at risk.