Globally, the numbers are even more staggering. Five researchers at Harvard’s T.H. Chan School of Public Health estimated that between 20 percent and 60 percent of everyone on earth — or between 1.4 billion and 4.2 billion people — could eventually contract the disease.
If the virus only kills 1 percent of those who contract it, somewhere between 14 million and 42 million people are at risk. In countries like Iran and Italy, where health systems are overrun, the mortality rate can be much higher.