What percentage of coronavirus cases result in no symptoms?
An opinion piece in today's print New York Times reports, "An estimated one in five people who develop Covid-19 never have symptoms."
That estimate conflicts with other information published by the Times. In August 2020, a Times news article reported:
The study's estimate that 30 percent of infected people never develop symptoms is in line with findings from other studies. In a television interview on Wednesday, Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, tendered 40 percent as the figure.
"The good news about Covid-19 is that about 40 percent of the population have no symptoms when they get infected," Dr. Fauci said.
The Times repeated the 40 percent estimate in a November 2020 news article: "up to 40 percent are asymptomatic, according to C.D.C. research."
As the Times news article reported, "Discussions about asymptomatic spread have been dogged by confusion about people who are 'pre-symptomatic' — meaning they eventually become visibly ill — versus the truly asymptomatic, who appear healthy throughout the course of their infection." That's a fair point. What's odd is the Times changing the number from 40 percent in the November news article to 20 percent in the February op-ed, without explaining to readers why the estimate for asymptomatic cases has suddenly been cut in half.