Is systemic dissemination of BCG following neonatal vaccination required for protection against M. tuberculosis?

Abstract

Tuberculosis (TB) is caused by Mycobacterium tuberculosis (Mtb) and is the leading cause of death. Bacillus Calmette-Guérin (BCG) is the only licensed TB vaccine. Preclinical studies have shown that in adults intravenous administration of BCG improves protection against TB. We hypothesize that intradermal administration of BCG to the human newborn leads to low grade BCG bacteraemia and that this systemic dissemination improves protection against Mtb infection. This hypothesis is based on supporting observations including animal and human studies. It is a testable hypothesis and offers to deliver immediately actionable insight to advance the global efforts against TB.