In our first article, Immunology 101: Innate and Adaptive Immunity Explained, we briefly introduced the concepts of the humoral immune response and the cell-mediated immune response as components of adaptive immunity. As a quick recall, adaptive immunity (also known as “acquired immunity”, since your body needs to “acquire” or learn to respond to the threat) enables the human body to quickly fight off foreign pathogens (e.g., bacteria, toxins, and viruses) through two main mechanisms: the humoral immune response, primarily driven by B cells, and the cell-mediated immune response, primarily driven by T cells.