An artistic model of a coronavirus infecting a cell. The family of viruses can cause mild infections, like the common cold, and severe pneumonia-like infections, such as SARS. Peter Kohama/MCT/Landov hide caption

itoggle caption Peter Kohama/MCT/Landov

Different types of coronaviruses can cause a simple cold or a deadly respiratory illness, such as SARS. BSIP/UIG via Getty Images hide caption

itoggle caption BSIP/UIG via Getty Images

Cheryl Gleasner, a research technologist at the Los Alamos National Laboratory, works with a genome sequencing machine designed for disease surveillance. Since the SARS epidemic in 2003, advances in sequencing technologies have greatly speed up the ability to detect and track a new virus. Ross D. Franklin/AP hide caption

itoggle caption Ross D. Franklin/AP