There are many compelling reasons to conclude that SARS-CoV-2, the virus that causes COVID-19, is not nearly as deadly as is currently feared. But COVID-19 panic has set in nonetheless. You can’t find hand sanitizer in stores, and N95 face masks are being sold online for exorbitant prices, never mind that neither is the best way to protect against the virus (yes, just wash your hands).
The public is behaving as if this epidemic is the next Spanish flu, which is frankly understandable given that initial reports have staked COVID-19 mortality at about 2–3 percent, quite similar to the 1918 pandemic that killed tens of millions of people.
Allow me to be the bearer of good news. These frightening numbers are unlikely to hold. The true case fatality rate, known as CFR, of this virus is likely to be far lower than current reports suggest. Even some lower estimates, such as the 1 percent death rate recently mentioned by the directors of the National Institutes of Health and the Centers for Disease Control and Prevention, likely substantially overstate the case.
We shouldn’t be surprised that the numbers are inflated. In past epidemics, initial CFRs were floridly exaggerated. For example, in the 2009 H1N1 pandemic some early estimates were 10 times greater than the eventual CFR, of 1.28 percent. Epidemiologists think and quibble in terms of numerators and denominators—which patients were included when fractional estimates were calculated, which weren’t, were those decisions valid—and the results change a lot as a result. We are already seeing this.
In the early days of the crisis in Wuhan, China, the CFR was more than 4 percent. As the virus spread to other parts of Hubei, the number fell to 2 percent. As it spread through China, the reported CFR dropped further, to 0.2 to 0.4 percent. As testing begins to include more asymptomatic and mild cases, more realistic numbers are starting to surface. New reports from the World Health Organization that estimate the global death rate of COVID-19 to be 3.4 percent, higher than previously believed, is not cause for further panic.
This number is subject to the same usual forces that we would normally expect to inaccurately embellish death rate statistics early in an epidemic. If anything, it underscores just how early we are in this.