He said he hesitated to state a number as high as 90% weeks ago because many Americans still seemed skeptical about vaccine.
“When polls said only about half of all Americans would take a vaccine, I was saying herd immunity would take 70 to 75 percent,” Dr. Fauci, who took his first dose of Moderna’s COVID-19 vaccine Tuesday, told The Times. “Then, when newer surveys said 60 percent or more would take it, I thought, ‘I can nudge this up a bit,’ so I went to 80, 85. -- https://www.washingtontimes.com/news/2020/dec/24/anthony-fau...
Further, this statement was made at approximately the same time that the UK variant was being discovered. There wasn't time for new R(t) numbers to be estimated. He was admitting to misleading us before the UK variant.
> Go straight to the science.
Yeah. So the model for herd immunity is well known: HI=(1-(1/R)). And we also have a good estimate of R(0) from CDC, about 2.5. That yields 60%. Following the science directly tells us that Fauci was actually telling the truth before, and it's today that he's lying.