Several states say they have been told to expect far fewer doses of the Pfizer-BioNTech COVID-19 vaccine in its second week of distribution, prompting worries about potential delays in shots for health care workers and long-term care residents.

But senior Trump administration officials on Thursday downplayed the risk of delays, citing a confusion over semantics, while Pfizer said its production levels have not changed.

The first U.S. doses were administered Monday, and already this week, hundreds of thousands of people, mostly health care workers, have been vaccinated. The pace is expected to increase next week, assuming Moderna gets federal authorization for its vaccine.

»Vaccine distribution tracker from The New York Times

Efforts to help ward off the coronavirus come amid a staggering death toll that surpassed 300,000 on Monday. Johns Hopkins University says about 2,400 people are dying daily in the U.S., which is averaging more than 210,000 cases per day.

In recent days, governors and health leaders in at least 10 states have said the federal government has told them that next week’s shipment of the Pfizer-BioNTech vaccine will be less than originally projected.

Little explanation was offered, leaving many state officials perplexed.

“This is disruptive and frustrating,” Washington Gov. Jay Inslee, a Democrat, wrote on Twitter on Thursday after learning from the Centers for Disease Control and Prevention that the state’s allocation would be cut by 40%. “We need accurate, predictable numbers to plan and ensure on-the-ground success.”

Missouri’s health director, Dr. Randall Williams, said his state will get 25% to 30% less of the vaccine next week than anticipated. A statement from the Iowa Department of Public Health said its allocation will be “reduced by as much as 30%, however we are working to gain confirmation and additional details from our federal partners.”

Michigan’s shipment will drop by about a quarter. Illinois, Montana, Kansas, Nebraska, New Hampshire and Indiana also have been told to expect smaller shipments.

In Washington, D.C., two senior Trump administration officials who spoke on condition of anonymity to discuss internal planning said states will receive their full allocations, but misunderstandings about vaccine supply and changes to the delivery schedule may be creating confusion.

One official said the initial numbers of available doses that were provided to states were projections based on information from the manufacturers, not fixed allocations. Some state officials may have misunderstood that, the official said.

The two officials also said that changes the federal government made to the delivery schedule, at the request of governors, may be contributing to a mistaken impression that fewer doses are coming. The key change involves spacing out delivery of states’ weekly allocations over several days to make distribution more manageable.

“They will get their weekly allocation, it just won’t come to them on one day,” one official said.

Pfizer made it clear that as far as production goes, nothing has changed.

“Pfizer has not had any production issues with our COVID-19 vaccine, and no shipments containing the vaccine are on hold or delayed,” spokesman Eamonn Nolan said in an email. “We are continuing to dispatch our orders to the locations specified by the U.S. government.”

The company said in a written statement that this week it “successfully shipped all 2.9 million doses that we were asked to ship by the U.S. Government to the locations specified by them. We have millions more doses sitting in our warehouse but, as of now, we have not received any shipment instructions for additional doses.”

The senior administration officials said Pfizer’s statement about doses awaiting shipping instructions, while technically accurate, conveniently omits the explanation: It was planned that way.

The federal officials said Pfizer committed to provide 6.4 million doses of its vaccine in the first week after approval. But the federal Operation Warp Speed had already planned to distribute only 2.9 million of those doses right away. Another 2.9 million were to be held at Pfizer’s warehouse to guarantee that individuals vaccinated the first week would be able to get their second shot later to make protection fully effective. Finally, the government is holding an additional 500,000 doses as a reserve against unforeseen problems.

Pfizer said it remains confident it can deliver up to 50 million doses globally this year and up to 1.3 billion doses in 2021.

Illinois Gov. J.B. Pritzker said Wednesday his state’s vaccinations are being cut almost in half, per Army Gen. Gustave Perna, the COO of the federal government’s Operation Warp Speed.

“Per the direction of Operation Warp Speed’s General Perna, that estimate was tightened significantly down to 4.3 million doses shipped nationally next week,” Pritzker said, according to 5Chicago. “The following week, originally projected for another 8.8 million, is also now also scheduled to be 4.3 million.”

In Michigan, a spokesperson for the Department of Health and Human Services told Crain’s Detroit the state is expecting only 60,000 of its scheduled 84,000 doses next week, an unexplained drop of 29%.

Federal officials previously told Michigan’s health agency the state would initially receive 84,000 weekly doses of Pfizer vaccine and 173,000 doses of the Moderna vaccine, which could get FDA approval for emergency use later this week.

Moderna COVID vaccine is shown to be safe, will likely be approved

On Tuesday, Florida Gov. Ron DeSantis said his state’s allotment may not arrive during the next two weeks because of production issues.

“We were supposed to get for next week 205,000 Pfizer and then the next week 247,000. Those next two weeks’ shipments of Pfizer are on hold right now,” DeSantis said. “We don’t know whether we will get any or not. And we’re just going to have to wait.”

On Wednesday, the federal government said 5.9 million doses of the Pfizer-BioNTech vaccine — enough to inoculate more than 2.9 million people — had been set aside mainly for states and territories to start protecting medical workers and nursing home residents against the coronavirus.

The first COVID-19 vaccinations are underway at nursing homes, including Florida, after nearly 2,000 such vaccinations were administered Tuesday in West Virginia. Thousands more are scheduled there in the coming days. Other states are expected to follow soon.

The elderly and infirm in long-term care have been among the most vulnerable to the virus and, together with health workers, are first in line to get the limited, initial supplies of the vaccine developed by Pfizer and Germany’s BioNTech. Nursing home residents and workers account for more than one-third of the nation’s 307,000 or so confirmed deaths from COVID-19.

West Virginia, with one of the oldest and unhealthiest populations in America, is working with small and local pharmacies to reach nursing homes across the heavily rural state, leapfrogging states that are relying on a partnership with the CVS and Walgreens drugstore chains to kick in any day now.

Marty Wright, head of the West Virginia Health Care Association, which represents nursing homes and assisted living communities, said the state’s pharmacies expect to get 7,000 doses into arms by the end of the week.

On Tuesday, the U.S. recorded more than 3,000 deaths for the third time in less than a week, eclipsing the peaks seen last spring. New cases are running at more than 212,000 a day on average. And the number of Americans in the hospital with COVID-19 hit another all-time high Tuesday of about 113,000.

A panel of independent experts is meeting Thursday to discuss the vaccine made by Moderna. The panel’s review for the Food and Drug Administration is the next-to-last step before the agency decides whether the shots can be used on an emergency basis. The FDA staff issued a positive review earlier in the week, confirming the vaccine’s safety and effectiveness.

If the panel gives a thumbs-up, the FDA is expected to give the green light within hours or days. A Pfizer vaccine got the go-ahead last week.

A second vaccine is urgently needed as coronavirus infections, hospitalizations and deaths keep rising in the U.S. ahead of the holidays. The U.S. leads the world in virus totals, with 17 million confirmed cases and more than 307,000 confirmed deaths.

Tim Darnell of The Atlanta Journal-Constitution contributed to this report.