Illustration of the French chemist and microbiologist Louis Pasteur (1822-1895), left, supervising his assistants experimenting on a rabbit during research into a rabies vaccine. Pasteur began his studies on rabies in 1880 infecting dogs, guinea pigs and rabbits with rabid saliva. He discovered that a vaccine could be obtained from the spinal cord of a rabid rabbit once kept in dry air for a few days. He was fearful of human trials but in 1885 he inoculated the vaccine into a nine year old boy who had been bitten by a rabid dog. The boy survived and in 1886 out of 2671 patients treated only 25 died.