Dr. Anthony Fauci said on Sunday that he did not deliberately move the goalposts for when the country would reach herd immunity, saying he was only offering "guestimates" before.

Fauci told New York Times that when polls said only about half of Americans would get the vaccine, he lowered the numbers to only 70 to 75 percent to reach herd immunity.

However, when more people started saying they will get vaccinated, Fauci also bumped up the herd immunity estimate to about 80 percent.

"We have to realize that we have to be humble and realize what we don't know. These are pure estimates," Fauci said.

Dr. Fauci And HHS Sec. Azar Receive COVID-19 Vaccinations During NIH Vaccine Kick-Off Event
(Photo : Patrick Semansky-Pool/Getty Images) Dr. Anthony Fauci speaks with Health and Human Services Secretary Alex Azar before receiving his first dose of the COVID-19 vaccine at the National Institutes of Health on December 22, 2020 in Bethesda, Maryland.

During the New York Times interview, Fauci also said some 90 percent may need to be vaccinated to achieve herd immunity.

However, he reiterated that the 75 to 80 percent estimate is within the correct range and most of his epidemiology colleagues even agree with him.

Fauci Says He Wasn't Sugarcoating

When he was asked if he "wasn't straight" with the public on herd immunity to begin with, Fauci said he was not sugarcoating his predictions, reported New York Post.

He clarified that when he said 70 to 75 percent, it was a "range" which is also within his projection of "70 to 85 percent."

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He also pointed out that the 15 percent leap was "not a big leap" when it comes to estimates.

During the interview, Fauci compared COVI-19 to measles and said it may not be "as contagious as measles"

"When you get below 90 percent of the population vaccinated threshold with measles, you start seeing a breakthrough against the herd immunity," he said.

This was why Fauci commented that COVID-19 may not be nearly as transmissible as measles since it as the "most transmissible" virus.

Senator Rubio Lashes Out on Fauci

Republican Senator Marco Rubio of Florida said Fauci as deceiving the public on the level of vaccination needed to achieve herd immunity, reported Daily Wire.

He also accused Fauci of lying to the public about the effectiveness of masks or face coverings against the virus.

 Rubio continued with the tweet, saying many other people in "elite bubbles" think the public doesn't know "what's good for them."

Fauci Continues to Encourage Vaccinations

Despite Rubio's accusations, Fauci continued to encourage people to get vaccinated both in the U.S. and globally.

In a Fox News report, he was quoted saying he uses any discussion or interview possible t reach the threshold for herd immunity.

In the past, Fauci said he believes that if the general public gets vaccinated by March 2021, herd immunity could be met by early summer, at the latest.

Related Story: Fauci Predicts US Could Reach Herd Immunity by Late Spring, Early Summer

But since general public vaccinations appear to have a starting date in April, herd immunity is projected to be reached by the end of summer, he said.

Vaccination numbers appeared to be lower than projected numbers by Operation Warp Speed a month ago, when vaccines were only awaiting approval.

Fauci said that with a comprehensive vaccine program this large, especially with a brand new vaccine, it is really expected to go slow at first and will gain momentum in time.