A nightmarish scene was burnt into my memory nearly two decades ago: Changainjie, Beijing’s normally chaotic “fifth avenue,” desolate without a sign of life. Schools shut, subways empty, people terrified to leave their homes. Every night the state TV channels reported new cases and new deaths. All the while, we had to face a chilling truth: the coronavirus, SARS, was so novel that no one understood how it spread or how to effectively treat it. No vaccines were in sight. In the end, it killed nearly 1,000 people.