Some administrative officials now say the number may be lower than they originally warned – but that is because there are continuing questions about how the administration came to the high number.
The latest number may end up higher or lower than the dramatic estimates released a week ago in an information meeting from the White House Coronavirus Task Force, according to federal health officials and researchers who create models to predict the outbreak.
A source close to the working group said it was possible that the final death toll would be “well below” the 100,000 to 240,000 figure.
A key factor driving the high estimate was a crucial assumption, discussed internally by the working group̵
“The models that were made assumed that only about 50% of the American public would heed the recommendations. It really seems like a large majority of the American public takes the Social Distance Council’s recommendations to heart – and I think that’s the direct consequence of why you see the numbers will be much, much, much, much lower than the models had predicted, “Redfield said.
The source close to the working group confirmed that Redfield cited the 50% figure discussed within the Coronavirus working group.
Health officials at the Coronavirus working group, led by Birx, based their estimates of 100,000-240,000 deaths on a number of models from a number of well-respected public health units at US top universities as well as the US Centers for Disease Control and Prevention.
The White House has not released the modeling calculations they have received or how they analyzed them.
Birx has often focused on the model of the University of Washington’s Institute for Health Metrics and Evaluation, whose estimated death toll has never been above 100,000 in recent weeks. This model assumes full compliance with social distance measures.
Institute for Health Metrics and Evaluation Director Christopher Murray said he has not seen how the working group deduced its range of 100,000 to 200,000 deaths, but that the figure overlaps with the range his group gave to the working group that projected 40,000 to 150,000 deaths.
CNN has learned that another of the models, from Imperial College London, predicted a worst case of up to 2.2 million deaths.
At a press conference at the White House on March 31, Birx said that with social distance, good hand hygiene and other steps, the death rate “can go down to 100,000 to 200,000 deaths, which is still too much.”
Public health experts warn that no one has a crystal ball with the ability to determine the exact number of people who will die in a pandemic. And they warn that despite the different numbers, there is no time to relax social distance measures.
Harvard researchers, who model the pandemic, also informed the White House of what the expected death toll might be, saying their estimates were similar to what Birx announced at a press conference.
“Our numbers were in that range,” said Mark Lipsitch, a professor of epidemiology at Harvard. “Ours was a little higher than the high part of their range because we used a higher R0,” referring to a measure of how contagious the virus is.
The White House also sought advice from Alessandr Vespignani, a professor at Northeastern University. He said his estimates were also “in the ballpark” with the figures Birx mentioned at the briefing.
In response to the White House email request for the model, Lipsitch said: “We delivered what we asked for as best we could, but I think all responsible modelers will say that our assumptions are wrong because we just don’t know the effectiveness of social distance. It’s pretty speculative. “
He added that none of the models leads to an optimistic conclusion about what all this will look like in the end.
“There are no good playoffs right now,” Lipsitch said.
Jeffrey Shaman, a professor at Columbia University’s Mailman School of Public Health, also provided a model for the working group. He said Birx’s estimate of 100,000 to 200,000 deaths is “not unreasonable.”
“Data will always trump models,” said working group member Dr. Anthony Fauci during a CNN City Hall on April 2.
Even before the working group released its official estimates, Fauci said the models could overestimate the number of Americans who can die from the virus, during an interview in CNN’s Union of State on March 29.
“The model is just as good and as accurate as your assumptions,” Fauci said. “And when the models come in, they give a worst case and a best case. In general, the reality is somewhere in the middle. I’ve never seen a model of the illnesses I’ve dealt with where the worst case actually came out. They always surplus.”
A source familiar with internal discussions about modeling and calculations said the 100,000-240,000 figure was not chosen to scare the public.
“The number was not chosen for a political or public relations purpose,” the source said.
CNN’s John Bonifield contributed to this report.