History of animal testing moment antibiotics were introduced, the fall became steep so that by the 1980s mortality in developed countries was effectively zero. In the 1940s, Jonas Salk used rhesus monkey cross-contamination studies to isolate the three forms of the polio virus that affected hundreds of thousands yearly. Salk's team created a vaccine against the strains of polio in cell cultures of rhesus monkey kidney cells. The vaccine was made publicly available in 1955 and reduced the incidence of polio 15-fold in the USA over the following five years. Albert Sabin made a superior "live" vaccine by passing the polio virus through animal
Jonas Salk "I had an opportunity to spend time in elective periods in my last year in medical school, in a laboratory that was involved in studies on influenza. The influenza virus had just been discovered about a few years before that. And, I saw the opportunity at that time to test the question as to whether we could destroy the virus infectivity and still immunize. And so, by carefully designed experiments, we found it was possible to do so." In 1941, during his postgraduate work in virology, Salk chose a two-month elective to work in the laboratory of Thomas Francis at