In a new document providing guidance for public health officials on COVID-19, the U.S. Centers for Disease Control and Prevention (CDC) estimates the infection fatality rate (IFR) for the disease at 0.4 percent, or about half the nearly one percent fatality rate the CDC estimated in March 2020 when it was predicting up to 1.7 million COVID-19 deaths in the United States.1 2 3 4 5 6
According to the document COVID-19 Pandemic Planning Scenarios, “The planning scenarios are being used by mathematical modelers throughout the Federal government. … The planning scenarios may also be useful to hospital administrators in assessing resource needs.”1 3 5
The CDC IFR estimate is slightly less than half the 0.9 percent estimate provided by an Imperial College London model published on Mar. 16, 2020 that forecast as many as 2.2 million deaths in the U.S. and significantly less than the 1-2 percent estimate given in March by Anthony Fauci, MD, director of the National Institute of Allergy and Infectious Diseases (NIAID).4 7 8 9 10
The CDC’s 0.4 percent rate, however, is for those who show symptoms of COVID-19. The CDC estimates that 35 percent of people who are infected with the SARS-CoV-2 virus never develop symptoms of the disease, which means that the IFR for the virus is 0.26 percent.1 2 3 4 That would place the fatality rate for the SARS-CoV-2 virus just slightly higher than that of seasonal influenza, which is estimated at 0.1 percent.8 9 10
In April, studies conducted by Stanford University and the University of Southern California estimated the IFR for COVID-19 at 0.1 percent to 0.2 percent, which places the rate in the same range at the new CDC rate. Both studies were criticized for underestimating the fatality rate for the disease. The CDC rate is now also attracting similar criticism.11 12
A study published in early May in Health Affairs by a professor at the University of Washington, Anirban Basu, estimated the COVID-19 symptomatic infection mortality rate in the U.S. to be 1.3 percent.13 Using data through Apr. 20, 2020, Professor Basu said that county-specific infection morality rates likely varied between 0.5 to 3.6 percent and that, “The overall IFR for COVID-19 should be lower when we account for cases that remain and recover without symptoms.”
Commenting on the CDC’s estimated 0.26 COVID-19 fatality rate, epidemiologist William Hanage, PhD of Harvard University’s T.H. Chan School of Public Health said, “If you’re taking these numbers to be your guide, they’re obviously lowball estimates.” Epidemiologist Joseph Lewnard, PhD agrees that the CDC’s fatality rates are “certainly at the very low end.5
“Greater clarity on the scientific basis for these estimates is urgently needed,” Dr. Lewnard said.5
In a recent analysis, Stanford epidemiologist John Ioannidis, MD estimated the IFR for COVID-19 at between 0.02 percent and 0.4 percent. “While COVID-19 is a formidable threat, the fact that its IFR is much lower than originally feared is a welcome piece of evidence,” wrote Dr. Ioannidis. “At a very broad, bird’s eye view level, worldwide the IFR of COVID-19 this season may be in the same ballpark as the IFR of influenza.”14 15
1 U.S. Centers for Disease Control and Prevention. COVID-19 Pandemic Planning Scenarios. May 20, 2020.
2 Rosenberg D. CDC: Coronavirus death rate likely just 0.26%. Arutz Sheva May 25, 2020.
3 Sullum J. The CDC’s New ‘Best Estimate’ Implies a COVID-19 Infection Fatality Rate Below 0.3%. Reason May 24, 2020.
4 Tennant M. CDC: COVID-19 Death Rate Far Lower Than Previously Thought. New American May 25, 2020.
5 Whyte LE. Scientists Say New, Lower CDC Estimates For Severity Of COVID-19 Are Optimistic Burszty. NPR May 22, 2020.
6 Fink S. Worst-Case Estimates for U.S. Coronavirus Deaths. The New York Times May 13, 2020.
7 Ferguson NM, et. al. Report 9: Impact of non-pharmaceutical interventions (NPIs) to reduce COVID-19 mortality and healthcare demand. Imperial College COVID-19 Response Team Mar. 16, 2020.
8 McCormack J. Coronavirus vs. the Flu: The Difference Between a 1% and 0.1% Fatality Rate Is Huge. National Review Mar. 14, 2020.
9 Sullum J. Is a 1% Case Fatality Rate for COVID-19 Bad News or Good News? Reason Mar. 12, 2020.
10 Watts A. Coronavirus mortality rate is about 2%, health official says. CNN Mar. 4, 2020.
11 Cáceres B. Study Estimates CA COVID-19 Mortality Rate Under One Percent. The Vaccine Reaction May 3, 2020.
12 Cáceres B. Stanford Study Suggests COVID-19 Mortality Rate Similar to Flu. The Vaccine Reaction Apr. 19, 2020.
13 Basu A. Estimating The Infection Fatality Rate Among Symptomatic COVID-19 Cases In The United States. Health Affairs May 7, 2020.
14 Ioannidis J. The infection fatality rate of COVID-19 inferred from seroprevalence data. medRxiv May 13, 2020.
15 Krieger LM. Stanford researcher says coronavirus isn’t as fatal as we thought; critics say he’s missing the point. The Mercury News May 20, 2020.