Dan Werb, PhD, is a writer and epidemiologist, with faculty positions in the Division of Infectious Diseases and Global Public Health at the University of California San Diego and at the Dalla Lana School of Public Health at the University of Toronto. Werb is the author of, most recently, The Invisible Siege: The Rise of Coronaviruses and the Search for a Cure, and has authored over one hundred epidemiological studies investigating the link between the spread of disease and social conditions