To slow the virus, Alessandro Vespignani and other analysts are racing to model the behavior of its human host. “Today, with the enormous computing power available on the cloud, Dr. Vespignani and other colleagues can model the entire world using” publicly available data, said Dr. Elizabeth Halloran, a professor of biostatistics at the University of Washington and a senior researcher at the Fred Hutchinson Cancer Research Center. “On the one hand, there is the rise of network science, and on the other, there is the enormous rise in computing power.”