Introductory Microbiology

Viral Diseases and Immunization

• The discovery of viruses and their role in disease was made possible when Charles Chamberland (1851-1908), one of Pasteur’s associates constructed a porcelain bacteria filter in 1884. The first virus to be recognized as filterable was tobacco mosaic virus, discovered by Russian, named Iwanowaskii (1882) and by Beijerinck (1899) in Holland. On the otherhand, filterable animal viruses were discovered for foot and mouth disease of cattle by Loffler and Frosch (1898), and for a human disease, yellow fever by the US army commission. Twort in England and d’ Herelle in France in 1916-1917 discovered viruses that infect bacteria i.e. bacteriophages. The first crystallization of virus was made by Stanley (1935).
• After this discovery, it was a matter of great surprise to the scientist that how animals resisted disease. Pasteur observed that old cultures of the bacterium attenuated i.e. lost their disease causing ability, they remain healthy but developed the ability to resist disease. He called the attenuated culture as Vaccine in respect of Edward Jenner because, several years back Jenner had used vaccination with material from cowpox lesion to protect people against smallpox. Emil Von Boehring (1854-1917) and Shibasaburo Kitasato (1852-1931) used inactivated toxin into rabbit, inducing them for antitoxin production. This is how a tetanus antitoxin was prepared and now used in the treatment.