(CNN) Dr. Anthony Fauci, US Health and Human Services Secretary Alex Azar and National Institutes of Health Director Dr. Francis Collins received their first doses of Moderna's Covid-19 vaccine Tuesday.
The shot, which Fauci, the director of the National Institute of Allergy and Infectious Diseases, received in the left arm, was administered at the NIH Clinical Center in Bethesda, Maryland, by Dr. Heike Bailin, chief of the NIH Occupational Medical Services.
"It's important for two reasons. One is that I'm an attending physician here at the National Institutes of Health Clinical Center, and so I do see patients," Fauci said as he was about to be vaccinated.
"But as important, or more important is as a symbol to the rest of the country that I feel extreme confidence in the safety and the efficacy of this vaccine and I want to encourage everyone who has the opportunity to get vaccinated so that we could have a valid protection over this country that would end this pandemic."
Azar, who also received the shot on his left arm, said that he has "absolute complete confidence in the integrity, and the independence of the processes used by the (US Food and Administration) to approve these vaccines."
Two coronavirus vaccines have received emergency use authorizations from the US Food and Drug Administration -- one made by Pfizer/BioNTech and another by Moderna.
Collins, who was also vaccinated on the left arm, became a emotional as he addressed the public before getting his shot.
"It's an incredible privilege to serve as the director of the National Institutes of Health, where so much of this work has been happening over the course of this tumultuous year. I get to talk a lot about these vaccines and their promise for ending this terrible global pandemic," Collins said.
"But it's one thing to hear me talk about it, it's another to have me roll up my sleeve and say I believe that this is the way we're going to get through this, this is something that the evidence has shown in rigorous scientific analysis to be safe and effective. So, I'm rolling up my sleeves and I'm saying, Dr. Bailin, bring it on!"
Six health care workers from the NIH Clinical Center and Colleen A. McGowan, director of the NIH Office of Research Services, also received vaccines.
Speaking on CNN hours after receiving the vaccine, Fauci said he feels fine.
"I feel very good. I feel perfectly normal," Fauci told CNN's Wolf Blitzer on Tuesday.
Fauci said he expects to develop some soreness in his arm.
"That's very common in any kind of vaccination, so I'm anticipating that, but in general, I feel fine," he said.