In 1908, Karl Landsteiner & Erwin Popper discovered a filterable agent as the cause of poliomyelitis. An extract of medula from a fatal human case was injected intraperitoneally in monkeys. He worked then at the Pasteur Institute, because no monkeys were available in the University of Vienna. The lesions that appeared were indistinguishable from those found in humans.
They could not pass the disease monkey to monkey, but Simon Flexner & Paul Lewis managed this and found antibodies. Arnold Netter & Constantin Levaditti found antibodies in human convalescents in 1908. Levaditti & Landsteiner demonstrated neutralizing antibodies in monkey serum against active virus. Frank Mcfarland Burnet & Jean MacNamara en 1931 demonstrated serotypes.