Why Some COVID-19 Cases Are Worse than Others

Emerging data as well as knowledge from the SARS and MERS coronavirus outbreaks yield some clues as to why SARS-CoV-2 affects some people worse than others.

Written byKatarina Zimmer
| 7 min read

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ABOVE: Colored visualization of electron microscopy photo of the coronavirus SARS-CoV-2
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Like many other respiratory conditions, COVID-19—the disease caused by SARS-CoV-2—can vary widely among patients. The vast majority of confirmed cases are considered mild, involving mostly cold-like symptoms to mild pneumonia, according to the latest and largest set of data on the new coronavirus outbreak released February 17 by the Chinese Center for Disease Control and Prevention.

Fourteen percent of confirmed cases have been “severe,” involving serious pneumonia and shortness of breath. Another 5 percent of patients confirmed to have the disease developed respiratory failure, septic shock, and/or multi-organ failure—what the agency calls “critical cases” potentially resulting in death. Roughly 2.3 percent of confirmed cases did result in death.

Scientists are working to understand why some people suffer more from the virus than others. It is also unclear why the new coronavirus—like its cousins SARS and MERS—appears to ...

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Meet the Author

  • katya katarina zimmer

    After a year teaching an algorithm to differentiate between the echolocation calls of different bat species, Katarina decided she was simply too greedy to focus on one field of science and wanted to write about all of them. Following an internship with The Scientist in 2017, she’s been happily freelancing for a number of publications, covering everything from climate change to oncology. Katarina is a news correspondent for The Scientist and contributes occasional features to the magazine. Find her on Twitter @katarinazimmer and read her work on her website.

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