Though more contagious variants are spreading in the United States, top health officials sounded notes of optimism on Sunday that both the supply of vaccines and the rate of vaccination will steadily increase.
“The demand clearly outstrips supply right now,” Dr. Anthony S. Fauci, the nation’s top infectious disease doctor, said on the NBC program “Meet the Press.”
“I can tell you that things are going to get better, as we get from February into March, into April, because the number of vaccine doses that will be available will increase substantially.”
The number of shots administered daily in the United States has increased lately. The Centers for Disease Control and Prevention reported that more than 2.2 million doses were given on Saturday, and 1.6 million on Friday. That brought the latest seven-day average to 1.4 million a day, which approaches President Biden’s new goal of 1.5 million shots per day.
In addition, the supply of vaccines — though still well below demand — is growing. Federal officials recently increased shipments to the states to 10.5 million doses a week, as Moderna and Pfizer gradually increase production. The two companies have deals to supply the United States with a combined 400 million doses — enough to vaccinate 200 million people — by the summer.
Pfizer recently said that it would deliver its doses two months ahead of schedule, by May, in part because it is now counting an additional dose in each vial it is manufacturing. And Moderna is considering a production change that would allow it to increase the number of doses in its vials to 15 from 10.
Officials are also counting on the Food and Drug Administration authorizing a one-dose vaccine from Johnson & Johnson later this month. Although that company will initially provide the United States with only a few million doses, it is expected to step up output considerably by April. Other vaccines from Novavax and AstraZeneca could also be authorized for U.S. use in the spring, further increasing supply.
Officials are racing to vaccinate as many people as possible in order to outpace more contagious variants of the virus that were first identified in Britain and South Africa. The variant from Britain, known as B.1.1.7, is spreading rapidly in the United States, with its prevalence doubling roughly every 10 days, according to a new study. The C.D.C. said it could become the dominant form of the virus in the United States by March.
Although that variant is worrisome because it is more transmissible than earlier variants, vaccine developers are more concerned about a variant discovered in South Africa, known as B.1.351, because it appears to make current vaccines less effective. Several manufacturers have said they are addressing the problem by developing new versions of their vaccines, which could act as booster shots. The Food and Drug Administration has said it is working on a plan to allow those new vaccine versions to be authorized.
Developers of the AstraZeneca and University of Oxford vaccine said on Sunday that they expected to have a modified version of their vaccine available by the fall.
On the CBS program “Face the Nation,” Dr. Scott Gottlieb, a former F.D.A. commissioner and a member of Pfizer’s board, said on Sunday that he believed it would be possible to develop a booster that “bakes in a lot of the different variations that we’re seeing.”
“I think that there is a reasonable chance that we’re going to be able to stay ahead of this virus,” he said.