a) Factors that influence the immune response:Stress: Acute stress causes release of adrenaline, which suppresses the immune response. Age: Maternal antibodies are meant to protectfrom disease but can interfere with vaccination and the own immune response. Nutrition: Nutrition plays a vital role in immunity. Exercise: regular, moderate exercise enhances immune response. Strenuous intermittent exercise result in oxidative damage to the cells and increases susceptibility to infections.Severe trauma results in immunodeficiency from the massive release of corticosteroids, prostaglandins and suppressive active peptide.Drug treatment may blunt the ability of the body to respond properly to immune challenge.
b) Antibodies are produced by the plasma T cells in the humoralimmunity. In cell mediated immunity, T cells induce the apoptosis of the infected cells. Humoral immunity destroysthe extracellular pathogens whereas cell mediated immunity destroys the intracellular pathogens. This is the differencebetween humoral and cell mediated immunity.