"Hopes of growing poliovirus in the lab without the use of live animals drove many researchers in the 1930s and 1940s. Cell cultures involve growing cells in a culture dish, often with a supportive growth medium like collagen. They offer a level of control unavailable using live animals, and can also support large-scale virus production. (For more about cell cultures and cell lines, as well as cell lines made using human cells, see our article “Human Cell Strains in Vaccine Development.”) Early efforts to grow poliovirus in culture, however, repeatedly ended in failure. In 1936, Albert Sabin and Peter Olitsky at the Rockefeller Institute successfully grew poliovirus in a culture of brain tissue from a human embryo. The virus grew quickly, which was promising, but Sabin and Olitsky were concerned about using this as starting material for a vaccine, fearing nervous system damage for vaccine recipients. They tried to grow poliovirus in cultures using tissue taken from other sources, but were unsuccessful."