The COVID-19 crash comes suddenly. In early March, the 37-year-old writer F. T. Kola began to feel mildly ill, with a fever and body aches. To be safe, she isolated herself at home in San Francisco. Life continued apace for a week, until one day she tried to load her dishwasher and felt strangely exhausted.
Her doctor recommended that she go to Stanford University’s drive-through coronavirus testing site. “I remember waiting in my car, and the doctors in their intense [protective equipment] coming towards me like a scene out of Contagion,” she told me when we spoke for The Atlantic’s podcast Social Distance. “I felt like I was a biohazard—and I was.” The doctors stuck a long swab into the back of her nose and sent her home to await results.
Lying in bed that night, she began to shake, overtaken by the most intense chills of her life. “My teeth were chattering so hard that I was really afraid they would break,” she said. Then she started to hallucinate. “I thought I was holding a very big spoon for some reason, and I kept thinking, Where am I going to put my spoon down?”
An ambulance raced her to the hospital, where she spent three days in the ICU, before being moved to a newly created coronavirus-only ward. Sometimes she barely felt sick at all, and other times she felt on the verge of death. But after two weeks in the hospital, she walked out. Now, as the death toll from the coronavirus has climbed to more than 150,000 people globally, Kola has flashes of guilt and disbelief: “Why did my lungs make it through this? Why did I go home? Why am I okay now?”
COVID-19 is, in many ways, proving to be a disease of uncertainty. According to a new study from Italy, some 43 percent of people with the virus have no symptoms. Among those who do develop symptoms, it is common to feel sick in uncomfortable but familiar ways—congestion, fever, aches, and general malaise. Many people start to feel a little bit better. Then, for many, comes a dramatic tipping point. “Some people really fall off the cliff, and we don’t have good predictors of who it’s going to happen to,” Stephen Thomas, the chair of infectious diseases at Upstate University Hospital, told me. Those people will become short of breath, their heart racing and mind detached from reality. They experience organ failure and spend weeks in the ICU, if they survive at all.
Meanwhile, many others simply keep feeling better and eventually totally recover. Kola’s friend Karan Mahajan, an author based in Providence, Rhode Island, contracted the virus at almost the same time she did. In stark contrast to Kola, he said, “My case ended up feeling like a mild flu that lasted for two weeks. And then it faded after that.”
“There’s a big difference in how people handle this virus,” says Robert Murphy, a professor of medicine and the director of the Center for Global Communicable Diseases at Northwestern University. “It’s very unusual. None of this variability really fits with any other diseases we’re used to dealing with.”
This degree of uncertainty has less to do with the virus itself than how our bodies respond to it. As Murphy puts it, when doctors see this sort of variation in disease severity, “that’s not the virus; that’s the host.” Since the beginning of the pandemic, people around the world have heard the message that older and chronically ill people are most likely to die from COVID-19. But that is far from a complete picture of who is at risk of life-threatening disease. Understanding exactly how and why some people get so sick while others feel almost nothing will be the key to treatment.