Sen. Marco Rubio on Sunday accused top U.S. epidemiologist Anthony Fauci of lying about the efficacy of masks and misrepresenting information about the number of people who must be vaccinated in order for the U.S. to achieve herd immunity against COVID-19.

"Dr. Fauci lied about masks in March[.] Dr. Fauci has been distorting the level of vaccination needed for herd immunity," Rubio, R-Fla., said in a tweet. "It isn’t just him Many in elite bubbles believe the American public doesn’t know 'what’s good for them' so they need to be tricked into 'doing the right thing.'"

Rubio's comment on the vaccines was likely addressing an interview Fauci gave to the New York Times on public health officials "quietly shifting" the percentage of the American public they say must get the vaccine to achieve "herd immunity." 

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"When polls said only about half of all Americans would take a vaccine, I was saying herd immunity would take 70 to 75%," Fauci said, according to the paper. "Then, when newer surveys said 60% or more would take it, I thought, ‘I can nudge this up a bit,’ so I went to 80, 85."

He continued: "We have to have some humility here...We really don’t know what the real number is. I think the real range is somewhere between 70 to 90%. But, I’m not going to say 90%."

The comment sparked outrage against Fauci for not allegedly leveling with Americans. 

"When you can't just 'trust the science' because the scientists keep lying to you and then saying, 'oh, that was just a noble lie, sorry about that,'" Ross Douthat, New York Times columnist, said of his paper's reporting. 

"We have to realize that we have to be humble and realize what we don't know. These are pure estimates," Fauci said Sunday on CNN's "State of the Union" about the New York Times interview. "The calculations that I made... it's a range... The reason I first started saying 70-75... it was really based on calculations and pure extrapolations from measles."

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Fauci also said the increase by about 10% in what he's said publicly is not very large. He went on to say "it's a bit of that" when asked more directly if he weighs polling in what he says publicly, adding "I want to encourage the people of the United States and globally to get vaccinated."

The other part of Rubio's tweet was directed at a stark reversal in public health recommendations on masks from the early stages of the pandemic when there had not been as much research into the virus and the U.S. was facing dire shortages of personal protective equipment.

Officials have said that a surge in supplies and evolving science -- not lies -- has led to the change in recommendations on masks. 

Surgeon General Jerome Adams in February exhorted Americans to "STOP BUYING MASKS." Months later, he, Fauci and the other American public health officials were saying that masks are the best way to stop the spread of the disease. 

Adams, in a White House Coronavirus Task Force Briefing in July, laid out what had changed. 

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"Health organizations and professionals originally recommended against the general public wearing masks because based on the best evidence available at the time, it was not deemed that it would have a significant impact on whether or not a health person wearing a mask would contract COVID-19. We have always recommended that symptomatic people wear a mask," Adams said. 

He added: "What has changed in our recommendation?... We now know from recent studies that a significant portion of individuals with coronavirus lack symptoms... And that even those who eventually become presymptomatic can transmit the virus to others before they show symptoms."

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Rubio's criticism of Fauci's messaging came days after he publicly took the coronavirus vaccine in an effort to instill confidence in the American public that the vaccine is safe. 

"I know I looked away from the needle[.] And yes, I know I need a tan," Rubio said in a tweet. "But I am so confident that the #Covid19 vaccine is safe & effective that I decided to take it myself."

Vaccinations of health workers and vulnerable elderly people continue in the final days of December, with vaccines steadily becoming more available for a broader number of people. Fauci on CNN's "State of the Union" on Sunday said he believes vaccines may be offered to the general public in late March or early April, leading to herd immunity potentially in the "middle to the end" of the summer.

He said that would lead to a "return to some form of normality" by the fall.