Copyright ©2005 Rockefeller University PressCasanova, J.-L. et al. J. Exp. Med. 2005;202:197-201Mortality curves at various periods of human historyImprovement of hygiene, beginning in the mid–19th century (preventing the transmission of infection)
Introduction of vaccines, beginning in the late 19th century (preventing disease in infected individuals)
Development of anti-infectious drugs, beginning in the early 20th century (preventing death in patients with clinical disease).