Boosting with mycobacterial heparin-binding haemagglutinin enhances protection of Mycobacterium bovis BCG-vaccinated newborn mice against M. tuberculosis.

Heterologous prime-boost regimens are a valuable strategy to improve the generation of effector-memory T cell responses against intracellular pathogens. In this study we show that newborn mice vaccinated with bacillus Calmette-Guérin (BCG) and boosted with heparin-binding haemagglutinin (HBHA) had enhanced protective immunity against intranasal or aerosol Mycobacterium tuberculosis challenge over non-boosted mice, as evidenced by a considerable reduction of mycobacterial load in spleen and lung. The route of HBHA delivery had a differential impact on cytokine and antibody production in BCG-primed mice.