Considering that BCGΔBCG1419c induced the recruitment of B lymphocytes during acute TB in T2D mice, this highlights the need to ascertain whether humoral immunity, per se or in combination with T CD8+ cells, plays any role in reduction of TB pathology upon vaccination with this particular vaccine candidate, as opposed to the T CD4+-driven response elicited by BCG. Here, CD4 is linked to type 2 diabetes mellitus.