The primary component of the human immune response is the white blood cells, particularly lymphocytes like B cells and T cells. B cells are responsible for producing antibodies that target specific pathogens, while T cells play a role in recognizing and destroying infected or cancerous cells. Both types are crucial for the adaptive immune response, which provides long-lasting immunity after exposure to pathogens. Additionally, macrophages and other leukocytes assist in the innate immune response, acting as the body's first line of defense against invading organisms.