Vicki Zhou spent New Year’s Eve in an emergency room—not as a patient, but as part of her first year as a doctor. The 27-year-old Zhou was wrapping up another eight-hour shift on the ER staff at the Hospital of the University of Pennsylvania in Philadelphia, and had to rush to a friend’s rooftop for the midnight fireworks.

“I made it in the nick of time,” Zhou says. “You could see all the skyscrapers, and we have fireworks on each side of the two rivers that border Philly.” But as she was enjoying the celebration, a contagion was rapidly multiplying inside the lungs of people in Wuhan, China. The year of coronavirus disease had begun.

Even without a global plague, it’s a