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excerpt: The chief reason the IHME projections worry some experts, Etzioni said, is that “the fact that they overshot”

Lipsitch: 2% of 70% of the HUMAN population equals approx 109 million deaths:

22 Apr: WaPo: Coronavirus outbreak edges closer to pandemic status
By Carolyn Y. Johnson, Lena H. Sun, William Wan and Joel Achenbach; Min Joo Kim in Seoul, Amanda Coletta in Washington and Chico Harlan and Stefano Pitrelli in Rome contributed to this report.
Harvard epidemiologist Marc Lipsitch estimates that 40 to 70 percent of the human population could potentially be infected by the virus if it becomes pandemic. Not all of those people would get sick, he noted. The estimated death rate attributed to covid-19 — roughly 2 in 100 confirmed infections — may also drop over time as researchers get a better understanding of how widely the virus has spread...
https://www.washingtonpost.com/health/coronavirus-outbreak-edges-closer-to-pandemic/2020/02/21/03afafc0-5429-11ea-9e47-59804be1dcfb_story.html

2% of 60% of the world’s ADULT population is still crazy numbers:

Tweet: Marc Lipsitch, Harvard
Because I am now less certain of where the R0 will end up (and how it may vary geographically) I am going to revise downward the range of outcomes I consider plausible to 20%-60% of adults infected. This involves subjectivity about what range of R0 may turn out to be true.
3 Mar 2020
follow-up Tweet:
To preempt the critique that the earlier figures were alarmist: I update my beliefs when the available data change, as any rational person would do. The available data are pointing to a different (and better) outcome than before. So I’m updating.
3 Mar 2020

Tweets 25 Feb:
The pace of new information is overwhelming, and some of the claims in this thread have shifted from speculative to factual or very nearly so. Other points need to be modified in light of new data ETC...

Summary: Should have said 40-70% of adults in a situation without effective controls.

Postscript: My original quote was in the @wsj which I thought had huge circulation. Around the same time I said the same to the @TheAtlantic. The WSJ article made some ripples, but the Atlantic one went completely viral. Not what I expected.
https://twitter.com/mlipsitch/status/1234879949946814464?lang=en

Lipsitch with Harvard’s Noah Feldman (Trump impeachment notoriety). asked about 40 to 70 of world population prediction, as told to WaPo (and others); Lipsitch says it was roughly correct, but he should have said “adult” population. said he is making amends:

AUDIO: 25:49 - Stitcher: Deep Background with Noah Feldman: The Coronavirus Isn’t Going Away
Marc Lipsitch, an epidemiologist at Harvard University, predicts that between 40 to 70 percent of adults in the world will become infected with the coronavirus.
https://www.stitcher.com/podcast/pushkin-industries/deep-background-with-noah-feldman/e/67663436

WaPo, others have never corrected the up to 70% claim, so don’t know where Lipsitch was making amends. certainly not in the following done after the Feldman interview. note how Axelrod gets in the “adult” bit which isn’t in the headline/opening:

2 Mar: CBS: Coronavirus may infect up to 70% of world’s population, expert warns
by Jim Axelrod
CBS News spoke to one of the country’s top experts on viruses, Marc Lipsitch from Harvard University, who cautions that 40-70% of the world’s population will become infected — and from that number, 1% of people who get symptoms from COVID-19, the disease caused by the coronavirus, could die...
Jim Axelrod: So, the number that I think is grabbing a lot of people is this estimate: 40-70% of the world’s adult population could be infected.
Marc Lipsitch: Yes.
Axelrod: Accurate?
Lipsitch: That is a projection, so we will find out if it’s accurate as things go on. It is the best estimate that I’ve been able to make based on a combination of the mathematical models that we use to track and predict epidemics...
https://www.cbsnews.com/news/coronavirus-infection-outbreak-worldwide-virus-expert-warning-today-2020-03-02/

a bit rich Sharon Begley/Stat News (formerly Newsweek/Daily Beast/Reuters) asking Lipsitch for a comment about IHME! you have to laugh.