Boosting with the subunit vaccine H65+CAF01 increased the BCG- protection against Mycobacterium bovis infection in a mouse model of bovine tuberculosis
H65, a fusion protein of three pairs of ESX-secreted antigens of Mycobacterium tuberculosis and Mycobacterium bovis, formulated with the liposomal adjuvant CAF01 has shown to confer protection against M. tuberculosis infection in mice. In this study, we evaluated the impact of H65+CAF01 immunization in combination with the BGC vaccine in a M. bovis mouse model of infection. We found that a BCG/H65+CAF01 prime-boost scheme induced higher protection than BCG and H65+CAF01 alone. In uninfected mice, this prime-boost vaccination significantly increased the number of CD4+IL-2+ and CD4+ KLRG1+ T cells upon antigen specific stimulation in comparison to non-vaccinated group. Altogether, H65 antigen formulated in liposomal adjuvant boosted the BCG-induced immune response, thus making this vaccine strategy a promising tool to control bovine tuberculosis.