Medical microbiology is both a branch of medicine and microbiology which deals with the study of microorganisms including bacteria, viruses, fungi and parasites which are of medical importance and are capable of causing infectious diseases in human beings. It includes the study of microbial pathogenesis and epidemiology and is related to the study of disease pathology and immunology. This branch of microbiology is amongst the most widely studied and followed branches due to its great importance to medicine. Along with providing a deep knowledge and understanding of the nature of pathogens this line of study has also been applied in several immunological innovations in the field of medical science. Through the development of vaccines against invading organisms, deadly and debilitating diseases such as small pox, polio, and tuberculosis have been either eradicated or are more treatable because of the efforts of scientists and researchers in the field of medical microbiology.