The era of modern microbiological and chemotherapeutical research begins, strictly speaking, with Pasteur (1822–1895), although much valuable preliminary work on infectious diseases and on their treatment and control had already been done by Jenner (1749–1823) and other workers. Pasteur can in fact be regarded as the father of modern bacteriology and chemotherapy, alongside such other pioneers as Lister (1827–1917), Koch (1843–1910), and, more especially, Ehrlich (1854–1915). Today, a century later, their methods and their discoveries are still fundamental and still form the model for further development.