As hundreds more American hospitals geared up Tuesday to vaccinate their workers, the face of the nation’s fight against the coronavirus said the U.S. could be back to normal by next fall.

On Monday, Dr. Anthony Fauci, who heads the National Institute of Allergy and Infectious Diseases, said the nation could achieve herd immunity against the coronavirus by “the end of the second quarter 2021,″ as vaccines are more widely deployed.

Depending on the “efficiency of the rollout,” Fauci told MSNBC that vaccines should be widely available to most Americans “sometime by the end of March, the beginning of April, that the normal healthy man and woman in the street who has no underlying conditions would likely get it.”

Fauci, who will continue as a central federal architect of the virus response in President-elect Joe Biden’s administration, said he believed most Americans who wanted the vaccine could probably get it by later March or early April.

Fauci hopes by late spring or early summer, the U.S. will attain “that umbrella of herd immunity.”

“By the time we get to the fall, we can start approaching some degree of relief where the level of infection will be so low in society we can start essentially approaching some form of normality,” he said.

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On Tuesday, Fauci told ABC’s “Good Morning America” that Biden and Vice President-elect Kamala Harris should be vaccinated for COVID-19 as soon as possible.

“For security reasons, I really feel strongly that we should get them vaccinated as soon as we possibly can.” He added he’d like to see Biden “fully protected as he enters into the presidency in January.”

Fauci says while President Donald Trump probably still has antibodies to the virus that will protect him for at least several months, he should get the vaccine as well to be “doubly sure.” Trump was hospitalized with COVID-19 in early October.

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Fauci said Vice President Mike Pence should get vaccinated, too. He said, “You still want to protect people who are very important to our country right now.”

On Tuesday, the U.S. Food and Drug Administration said its preliminary analysis confirmed the effectiveness and safety of the vaccine developed by Moderna and the National Institutes of Health, bringing it to the cusp of U.S. authorization.

A panel of outside experts is expected to vote to recommend the vaccine on Thursday, with a final FDA decision coming soon thereafter.

The positive news came as hospitals ramped up vaccinations with the shot developed by Pfizer and BioNTech, which the FDA cleared last week. The Moderna vaccine uses the same technology and showed similarly strong protection against COVID-19.

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Packed in dry ice to stay at ultra-frozen temperatures, shipments of Pfizer’s COVID-19 vaccine began arriving at 400 additional hospitals and other distribution sites, one day after the nation’s death toll surpassed a staggering 300,000. The first 3 million shots are being strictly rationed to frontline health workers and elder-care patients, with hundreds of millions more shots needed over the coming months to protect most Americans.

Vaccinations were expected to kick off Tuesday in New Jersey, which is dividing some 76,000 doses among health workers and nursing home residents. The federal government is coordinating the massive delivery operation by private shipping and distribution companies based on locations chosen by state governors.

Following another initial set of deliveries Wednesday, officials with the Trump administration’s Operation Warp Speed said they will begin moving 580 more shipments through the weekend.

“We’re starting our drumbeat of continuous execution of vaccine as it is available,” Army Gen. Gustave Perna, chief operating officer for Warp Speed, told reporters Monday. “We package, and we deliver. It is a constant flow of available vaccine.”

Perna and other U.S. officials reiterated their projection that 20 million Americans will be able to get their first shots by the end of December — and 30 million more in January.

That projection assumes swift authorization of the Moderna vaccine, which also requires two shots for full protection. The U.S. government has purchased 100 million doses of the Pfizer vaccine and orders for 200 million doses of the Moderna vaccine. Assuming no manufacturing or distribution delays, that would be enough to vaccinate 150 million Americans by mid-2021.

Moderna’s vaccine is the same type as Pfizer’s, made with the same technology. And in scrutinizing early results of a 30,000-person study, the FDA found it also worked just about the same.

The Moderna vaccine was more than 94% effective overall at preventing COVID-19 illness and 86% effective in people 65 and older. The FDA uncovered no major safety issues.

Recipients tend to experience temporary flu-like side effects that can include fever, fatigue and aches, especially after the second dose as the vaccine revs up their immune system.

The Associated Press contributed to this report.