Emerging infectious diseases are clearly recognized as threats to human health and a significant public health problem. New emerging pathogens lists published prior to 2002 included HIV, influenza, the filoiviruses, hantaviruses, and various arboviruses, recognizing that many emerging pathogens were zoonotic in origin. Despite the recognition that new emerging viruses are difficult if not impossible to predict, standardized lists were developed based primarily on epidemiologic trends over the past ∼50 years. Another consistent theme was the near universal agreement that coronaviruses were not emerging pathogens, but rather were only associated with relatively benign upper respiratory tract infections in humans.