Dr. Marc Lipsitch, Ph.D, an Associate Professor of Epidemiology and Immunology and Infectious Diseases at Harvard School of Public Health presented a lecture at the Library of Congress on February 7, 2005. The lecture was on "The Transmission of SARS (Severe Acute Respiratory Syndrome) and Influenza : Lessons from the Past and How We Should be Preparing for the Future." Dr. Lipsitch’s talk was partially based on his most recent publication in Nature, Vol. 432, 16 December, 2004, p. 904-906.