Historical Aspects

The first animal influenza A virus was isolated in 1931 by Richard Shope. The virus caused a highly contagious, influenza-like disease in pigs. Two years later, in 1933, the first human influenza A virus was isolated by Wilson Smith and colleagues. Soon after, in 1940, a representative of influenza virus type B was discovered by Thomas Francis, Jr. Being obligate intracellular parasites, viruses can be cultivated only within sensitive substrates. Three main substrates for the cultivation of influenza viruses are known: sensitive animals, embryonated chicken eggs, and tissue cultures. Today, in the twenties of the 21st century, sensitive animals are not often used for the isolation of the infectious virus. However, they are widely used to study and model a number of infectious diseases, including influenza. A list of these animals used for influenza research is very long, starting from ferrets and mice and ended with exotic zebrafish.

Keywords: Animal models, Embryonated chicken eggs, First human influenza viruses, Influenza, Nomenclature, Tissue culture.