Neonatal revaccination with Bacillus Calmette-Guérin elicits improved, early protection against Mycobacterium tuberculosis in mice

► Revaccination of neonatal mice with BCG elicits improved, early protection against Mycobacterium tuberculosis in mice. ► The IFN-γ responses are not ideal and accurate biomarker for evaluating the efficacy of BCG vaccination against M. tuberculosis infection in mice. ► Neonatal vaccination with BCG modulates M. tuberculosis infection-induced immune responses in adult mice.