CD4 and tuberculosis: Noteworthy, another study showed that PBMCs isolated from HIV-infected and BCG-vaccinated adults with a CD4+ count ≥ 200 cells/mL administered with five intradermal doses of whole cell heat-inactivated M. vaccae NCTC 11659 further showed a boosted IFNγ production and proliferation when exposed in vitro to M. vaccae NCTC 11659 sonicated at a concentration of 2 μg/mL over five days [45]; in addition, an increased serum antibody response to lipoarabinomannan, indicative of protective immunity against TB, was detected following treatment with M. vaccae NCTC 11659 in HIV-infected adults [45].