BCG has its own issues, though. Immunity wanes after awhile, the protection is incomplete and it seems to be more effective at preventing extrapulmonary disease

BCG has its own issues, though. Immunity wanes after awhile, the protection is incomplete and it seems to be more effective at preventing extrapulmonary disease than pulmonary. This by no means says it's useless. It has probably greatly diminished pediatric tuberculous meningitis in at-risk counties, which can be devastating (one of my nightmare cases was a two-year-old who lost part of his occipital lobe to contaminated dairy). In low-prevalence countries, however, where pulmonary TB is the primary concern, its utility is questionable. https://www.cdc.gov/tb/publications/factsheets/prevention/bcg.htm https://www.cdc.gov/tb/publications/factsheets/prevention/bc...