CD4 and pneumonia: On the other hand, BCGΔBCG1419c was able to confer protection against TB via the maintenance of B and T CD8+ lymphocytes during acute TB, favoring the latter as opposed to T CD4+ lymphocytes being more attracted to lungs in response to BCG, and by increasing IL-1β production during chronic TB, outperforming BCG in reducing pneumonia in advanced TB-T2D.