As winter storms threatened to upend distribution of Covid-19 vaccines, the White House on Tuesday said that states collectively would begin receiving 13.5 million doses each week — a jump of over two million doses due in part to a shift in the way the government is allocating doses of Pfizer’s vaccine. And Jen Psaki, the White House press secretary, said that a new federal pharmacy program will now provide two million weekly doses, a doubling of its initial supply.
The increases were welcome developments for state officials desperate to inoculate more vulnerable Americans before more contagious variants of virus become dominant.
The Biden administration has been working with Pfizer, the maker of one federally authorized vaccine, to get the company more manufacturing supplies, including pumps and filtration units, through the Defense Production Act. The administration announced last week that Pfizer and Moderna, the other maker of the vaccine authorized in the United States, will be able to deliver a total of 400 million doses by the end of May, well ahead of schedule.
The latest boost in supply came partly because Pfizer, as of this week, is getting credit for six doses instead of five doses per vial, a White House spokesman said. Two-thirds of the boost was due to increased output, the spokesman said. Officials now say there is an ample supply of specialized syringes needed to extract the extra Pfizer dose. The White House warned state officials last week that because of that accounting change, the number of doses that the federal government said it had delivered would shoot up, even if the amount of vaccine in each vial itself did not.
Ms. Psaki told reporters on Tuesday that with the latest increase, vaccine deliveries had jumped 57 percent since President Biden was inaugurated. Administration officials have regularly framed those increases as Mr. Biden’s accomplishment, even though, at least to some degree, the supplies were expected to grow as Pfizer and Moderna ramped up manufacturing.
The announcement on Tuesday came as winter storms in the South continued to disrupt vaccine distribution. Clinics were closed and shipments were stalled in states where the pace of vaccinations already had lagged behind the national average. Vaccine appointments were rescheduled or canceled from Texas to Kentucky.
A spokeswoman for the Centers for Disease Control and Prevention said Tuesday that the government was projecting “widespread delays” in vaccine shipments and deliveries in the coming days, as weather was affecting a FedEx facility in Memphis and a UPS facility in Louisville, both vaccine shipping hubs.
“C.D.C. and federal partners are working closely with the jurisdictions, as well as manufacturing and shipping partners, to assess weather conditions and help mitigate potential delivery delays and cancellations,” the spokeswoman said.
Ms. Psaki said that officials were monitoring the storms and in touch with state and local governments. She said there was a “contingency plan to ensure people are getting the doses they need at an appropriate timeline.”
The increase in doses for pharmacies announced on Tuesday came after White House officials had warned that supplies to that program would be extremely limited in the beginning. More than 40,000 pharmacies are expected to receive doses as part of the program.
Mr. Biden and top federal health officials have offered varying estimates of when most Americans might be able to receive a vaccine. The president last week announced that the federal government had secured 200 million more doses, bringing the total amount promised to 600 million, or enough to cover 300 million Americans. But he warned that logistical hurdles would most likely mean that many Americans will still not have been vaccinated by the end of the summer.
On Tuesday, Dr. Anthony S. Fauci, the nation’s top infectious disease expert and adviser to Mr. Biden, revised his own estimate from last week, when he predicted the beginning of an “open season” by April. “That timeline will probably be prolonged, maybe into mid-to-late May and early June,” he said in an interview with CNN.
Campbell Robertson contributed reporting.