Birx recently confronted Vice President Pence, who chairs the task force, about the acrimony, according to two people familiar with the meeting. Birx, whose profile and influence has eroded considerably since Atlas’s arrival, told Pence’s office that she does not trust Atlas, does not believe he is giving Trump sound advice and wants him removed from the task force, the two people said.

Pence did not take sides, but rather told Atlas and Birx to bring data bolstering their perspectives to the task force and to work out their disagreements themselves, according to two senior administration officials…

At a task force meeting late last month, Atlas stated that there was herd immunity in much of the country because of a combination of high infection rates in cities such as New York and Miami and T-cell immunity, according to two senior administration officials. He said that only 40 to 50 percent of people need to be infected to reach the threshold. And he argued that because of this immunity, all restrictions should be lifted, schools should be opened and only the most vulnerable populations, such as nursing home residents, should be sheltered.

This resulted in a fierce debate with Birx and Fauci, who demanded Atlas show them the data that backed up his assertions, one of the officials said.

“It is not the case there’s extra immunity around in T cells,” Lipsitch said. “The vast, vast majority of infectious-disease epidemiologists in this country don’t believe several of the key points these people are arguing for and don’t believe it because the evidence isn’t there and points in the other direction.”