.... vaccine gives considerable protection against tuberculosis.

The right answer is BCG

T-cells are targeted as the AIDS parasitizes the CD4+ molecules on their surface. Our body fights back the HIV infections producing another 2 billion cells to replace the infected ones stabilizing the T-cells count temporarily. Yet from day one, the T-cells fight a losing battle. Although HIV target T-cells and other cells in the body, HIV thrives mainly in the lymph nodes and the other immune parts of our body.