The U.S. will have enough COVID-19 vaccines available before March 2021 to vaccinate up to 100 million Americans, or about one-third of the nation's population, a top adviser to the White House said.

In addition to the 40 million doses of COVID-19 vaccines expected by the end of December — 20 million from Pfizer Inc. and BioNTech SE and 20 million from Moderna Inc. — which will be enough to vaccinate 20 million people, there should be sufficient supplies of those products by the end of February 2021 to vaccinate another 80 million, Moncef Slaoui, chief scientific adviser for the White House's Operation Warp Speed public-private partnership, told reporters.

The Pfizer-BioNTech and Moderna vaccines are two-dose shots.

The companies could have 60 million doses ready in January 2021, or enough for 30 million people, and 100 million doses in February, sufficient for another 50 million people, Slaoui said.

Those available doses will more or less cover a significant portion of the at-risk population — older Americans, healthcare personnel, essential workers and people with comorbidities, Slaoui said.

The U.S. Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices, or ACIP, voted 13 to 1 on Dec. 1 that healthcare personnel and residents and staff of long-term care facilities should be first to get the COVID-19 vaccines when they are authorized by the U.S. Food and Drug Administration.

Pfizer and its partner BioNTech and Moderna, which collaborated with the U.S. National Institute of Allergy and Infectious Diseases, or NIAID, are awaiting decisions from the FDA on whether the agency will grant emergency use authorization, or EUA, to the companies to market their products.

The FDA's Vaccines and Related Biological Products Advisory Committee, or VRBPAC, is scheduled to review the Pfizer-BioNTech EUA application Dec. 10 and Moderna's EUA submission Dec. 17. The agency could act within hours of those meetings.

Even more Americans may get vaccinated under Slaoui's timeline if Johnson & Johnson's Janssen Pharmaceuticals unit is able to get its one-dose vaccine through clinical testing and onto the U.S. market, he said. AstraZeneca PLC may also have a vaccine ready for the FDA's review by early 2021, Slaoui added.

Allocation

All 64 U.S. jurisdictions — 50 states, eight territories and six "mega-cities" — as well as five federal agencies have already been notified of their initial allocations of the vaccines, or the number of doses, they will receive in December, Gen. Gustave Perna, Warp Speed's chief operating officer, told reporters.

For planning purposes only, the jurisdictions and the five federal agencies — the Departments of Veterans Affairs, Defense and State; the Indian Health Service; and the Federal Bureau of Prisons — were told to expect shipments to start arriving in mid-December, based on the dates of the VRBPAC meetings, Perna said.

Half of the allocations will be shipped, with the other half held back until it is time to give the second doses — 21 days later for the Pfizer-BioNTech vaccine and 28 days for the Moderna-NIAID product, Perna said.

The 40 million doses are not being sent all at once to avoid over-administration, to ensure there will be the second doses available when needed and to prevent the jurisdictions' limited storage capacity from being overwhelmed, he said.

The jurisdictions were told to submit their final distribution plans to the CDC by Dec. 4, Perna said.

Warp Speed is using a data platform system, known as Tiberius, to track and manage the allocation of the vaccines to states, hospitals, doctors' offices and pharmacies, he said.

The goal is to maintain a cadence of delivery as new batches of vaccine doses become available, Perna said.

"We want to enable and empower the jurisdictions to execute their plans," he said. "That is our sole goal, our responsibility to do."

But states and their public health agencies have complained they lack the funding to carry out the mass vaccination program in the U.S.

The Association of State and Territorial Health Officials told Congress in October that the $200 million the CDC provided states fell far short of the nearly $9 billion that is needed.

President-elect Joe Biden has endorsed a bipartisan COVID-19 stimulus bill that would provide $16 billion for vaccine development and distribution, as well as testing and tracing.

Education

The Warp Speed officials acknowledged part of the challenge will be getting Americans to take the COVID-19 vaccines and they urged people to educate themselves about the products.

"Be informed in your process," Perna said. "Don't allow one headline to determine what you're going to do."

While earlier surveys showed about half of Americans said they were reluctant to get the COVID-19 shots, the latest Gallup poll found acceptance of the vaccines is growing, with about 58% of the respondents saying they would get vaccinated.

However, CDC officials noted at a Nov. 23 ACIP meeting that a recent survey of nurses showed only 34% of those professionals said they would voluntarily get vaccinated if they were not mandated by their employers to do so.

Former President Barack Obama, whose administration funded and launched the research into the messenger RNA platform used for the NIAID-Moderna vaccine, said Dec. 2 he would be willing to help that education effort by getting the COVID-19 shot on live TV or have it taped "so people know that I trust this science."

"Vaccines are why we don't have polio anymore and they're the reason why we don't have a whole bunch of kids dying from measles, smallpox and diseases that used to decimate entire populations and communities," Obama said on SiriusXM's "The Joe Madison Show."