In the midst of one of the deadliest phases of the pandemic in the United States, health officials around the country are growing desperate, unable to get clear answers as to why the long-anticipated vaccines are suddenly in short supply.
Inoculation sites are canceling thousands of appointments in one state after another as the nation's vaccines roll out through a patchwork of distribution networks, with local officials uncertain about what supplies they will have in hand.
The situation is especially dire in Texas, which is averaging about 20,000 new coronavirus cases a day, fueling concerns over whether officials will be able to curb the spread with vaccines in such short supply.
Dr. Esmaeil Porsa, the CEO of Harris Health System in Houston, which treats thousands of mostly uninsured patients, warned Friday that its entire vaccine supply could be depleted by midday Saturday.
In South Carolina, one hospital in Beaufort had to cancel 6,000 vaccination appointments after the city received only 450 of the doses it expected. In Hawaii, a Maui hospital canceled 5,000 first-dose appointments and put 15,000 additional requests for appointments on hold.
In San Francisco, the public health department had at one point expected to run out of vaccines last week because the city's allocation dropped sharply from the week before, and California officials temporarily had to put thousands of doses on hold after a higher-than-usual number of possible allergic reactions was reported.
In New York state, officials in Erie County canceled thousands of vaccination appointments in recent days after a sharp decline in allocations from the state.
Health officials trying to piece together why this is happening are puzzled by reports that millions of available doses are going unused. As of Friday morning, nearly 39.9 million doses of the Pfizer-BioNTech and Moderna vaccines had been distributed to state and local governments, but only about 19.1 million doses had been administered to patients, according to the Centers for Disease Control and Prevention.
Pfizer and Moderna have each agreed to provide the United States with 100 million vaccine doses, and the companies are racing to manufacture the vaccines, together releasing between 12 million and 18 million doses a week.
At that rate, it is feasible for the new administration to meet President Joe Biden's pledge to inject 100 million doses by his 100th day in office. Public health officials could even potentially ramp up the pace of vaccinations with the existing supply.
Distribution of the already available doses has been a major cause of the acute vaccine shortages now being seen in parts of the country. Factor in the ever-increasing demand as more states make the vaccine widely available to people 65 and older, and officials warn that distribution headaches will persist in the weeks ahead.
The Biden administration has pledged to overhaul distribution to the states and even use the Defense Production Act to increase supply, but vaccine experts warn that shortages of the doses will persist in the short term with manufacturing sites already facing capacity constraints.
State and local governments, as well as hospital administrators, are fending for themselves. In Houston, Porsa said his staff was scrambling as the supply of vaccines dwindled last week, squeezing six doses out of vials intended to provide five.
The sense of chaos afflicting the distribution efforts in many states is laying bare how local officials are struggling to fill the void left by the lack, until last week, of a comprehensive response at the federal level.
Dr. George Rutherford, a public health researcher at the University of California, San Francisco, said the most obvious problem with vaccine administration in the San Francisco area was clear.
"There's not enough doses, period," he said. "That's it. Everything would work fine if you had enough doses."
The public health department in San Francisco and hospitals in the city were "caught by surprise" by the lack of doses, Rutherford said, and by the eligibility expansion to people 65 and older, which likely strained the system. Varying vaccine distribution channels -- such as Kaiser Permanente and the University of California-San Francisco -- receive the doses on their own, he said, further complicating an already convoluted distribution system.
"So it's a little hard for the city to understand exactly what's left over, what they need to do, where the holes are to fill," Rutherford said.
Still, new vaccination sites are opening in San Francisco, which Rutherford said would help speed the process along once more doses become available.
"There's this tension between efficiency and equity," he said. "It's never easy."
Dr. Grant Colfax, head of the San Francisco Department of Health, said the city was "very close to doses running out" and said a lack of overall coordination has led to distribution problems.
"I think what this really is, is a continuation of the fallout of the lack of a coordinated federal response," he said. "Basically cities and counties were left on our own to deal with this pandemic."
Meanwhile, the coronavirus variant first spotted in Britain is spreading at an alarming rate and isn't responding to established ways of slowing the pandemic, according to Danish scientists who have one of the world's best views into the new, more contagious strain.
Cases involving the variant are increasing 70% a week in Denmark, despite a strict lockdown, according to Denmark's State Serum Institute, a government agency that tracks diseases and advises health policy.
"We're losing some of the tools that we have to control the epidemic," said Tyra Grove Krause, scientific director of the institute, which last week began sequencing every positive coronavirus test to check for mutations. By contrast, the United States is sequencing 0.3% of cases, ranking it 43rd in the world and leaving it largely blind to the variant's spread.
British Prime Minister Boris Johnson on Friday suggested for the first time that the variant may be more deadly than the original virus. Because it can spread more easily, it can also quickly overwhelm medical systems, turning previously survivable bouts with the virus into perilous ones if hospitals are full and medical care is limited.
Danish public health officials say that if it weren't for their extensive monitoring, they would be feeling a false sense of confidence right now. Overall, new daily confirmed cases of the coronavirus in Denmark have been dropping for a month.
"Without this variant, we would be in really good shape," said Camilla Holten Moller, the co-leader of the State Serum Institute group modeling the spread of the virus.
"If you just look at the reproduction number, you just wouldn't see that it was in growth underneath at all," she said.
But the British variant is spreading so quickly that Danish authorities project it will be the dominant strain of the virus in their country as early as mid-February.
That would put Denmark ahead of the United States, where the CDC warned Friday that the U.K. variant, known as B.1.1.7, could be prevalent by March.
As much of the world grapples with the spread of the virus, life has largely returned to normal in the Chinese city of Wuhan, the site of the world's first coronavirus lockdown last March.
Wuhan accounted for the bulk of China's 4,635 deaths from covid-19, a number that has largely stayed static for months. The city has been largely free of further outbreaks since the lockdown was lifted on April 8, but questions persist as to where the virus originated and whether Wuhan and Chinese authorities acted fast enough and with sufficient transparency to allow the world to prepare for a pandemic that has sickened more than 98 million.
Wuhan has been praised for its sacrifice in the service of the nation, commemorated in books, documentaries, TV shows and speeches from officials, including head of state and leader of the Communist Party Xi Jinping.
"We think Wuhan is a heroic city. After all, it stopped its economy to help China deal with the pandemic. This is a noble act," said resident Chen Jiali, 24, who works at an internet shopping company.
China on Saturday announced another 107 cases, bringing its total since the start of the pandemic to 88,911. Of those, the northern province of Heilongjiang accounted for the largest number at 56. Beijing and the eastern financial hub of Shanghai both reported three new cases amid mass testing and lockdowns of hospitals and housing units linked to recent outbreaks.
Authorities are wary of the potential for a new surge surrounding next month's Lunar New Year holiday and are telling people not to travel and to avoid gatherings as much as possible. Schools are being let out a week early and many have already shifted to online classes.
Mask wearing remains virtually universal indoors and on public transport. Mobile phone apps are used to trace people's movements and prove they are virus-free and have not been to areas where suspected cases have been found.
Since the end of the lockdown, Wuhan has largely been spared further outbreaks, something residents such as chemistry teacher Yao Dongyu attribute to heightened awareness resulting from the traumatic experience of last year.
"At that time, people were very nervous, but the government gave us huge support. It was a very powerful guarantee, so we got through this together," said Yao, 24. "Since Wuhan people went through the pandemic, they've done better in personal precautions than people in other regions."
China has doggedly defended its actions in the early days of the outbreak, saying it helped buy time for the rest of the world while pushing fringe theories that the virus was brought to the city from outside China, possibly from a laboratory in the U.S.
Meanwhile, in Hong Kong, thousands of residents were on lockdown Saturday in an unprecedented move to contain a worsening outbreak in the city.
Hong Kong has been grappling to contain a fresh wave of the coronavirus since November. More than 4,300 cases have been recorded in the past two months, making up nearly 40% of the city's total.
Information for this article was contributed by Emily Wang Fujiyama of The Associated Press; by Simon Romero and Giulia McDonnell Nieto del Rio of The New York Times; and by Michael Birnbaum and Martin Selsoe Sorensen of The Washington Post.