Immune System - The system of biological structures and processes that protects the body from foreign substances, including pathogens.⏎
Infectious Disease - A type of illness caused by a pathogenic agent, including viruses, bacteria, fungi, protozoa, parasites, or abnormal proteins known as prions.⏎
Metabolism - The sum total of chemical reactions that occur within a living cell both to build new molecules within the cell and break down and assimilate sources of energy for the cell.⏎
Incubation Time - The period of time between exposure to an infectious agent and the appearance of symptoms of the infection or disease it causes.⏎
Morbidity - The relative occurrence of a disease or a condition that causes illness.⏎