Two pieces of economic data released Thursday highlight the pain of the U.S. economy as the coronavirus pandemic rages on.

Some 847,000 people nationwide lost their jobs and filed for unemployment insurance last week, according to the U.S. Department of Labor. That's a decrease of 67,000 compared to the previous week’s figure.

In addition, the Department of Labor said more than 18 million people were still claiming some form of unemployment benefits through all U.S. government programs as of the week ending Jan. 9. For the comparable week last year, that number was approximately 2 million.

While the weekly unemployment filings figure has dropped off significantly since peaking at some 6.9 million in a single week last spring, they still remain at historically high levels.

Meanwhile, the U.S. Department of Commerce said Thursday that U.S. gross domestic product grew at a 4% annualized rate last quarter -- a significant slowdown compared to the previous quarter, which saw an increase of 33.4% on an annualized basis. The third quarter’s huge spike, however, reflected businesses reopening after mass shutdowns.

ABC News’ Catherine Thorbecke contributed to this report.

Dr. Anthony Fauci, chief medical adviser to U.S. President Joe Biden and the nation's leading infectious disease expert, said Americans can expect to see more COVID-19 vaccine doses available throughout the country in the coming weeks.

"As we get into February, March and April, we're going to see an escalation of availability of doses that we may have not had a week or two or three ago," Fauci, who is also the director of the National Institute of Allergy and Infectious Diseases, told ABC News chief anchor George Stephanopoulos Thursday on "Good Morning America."

Although COVID-19 data is starting to show some promising trends, Fauci said the U.S. outbreak is "still a very serious situation."

"If you look throughout the country, the dynamics of the outbreak are a little bit unstable," he noted, "even though for the most part we're seeing general trends, seven-day trends of cases going down and ultimately, hopefully, hospitalizations and deaths."

When asked about reopening schools safely, Fauci said COVID-19 transmission rates in schools actually appear to be less than in communities when the schools have the resources and protection they need.

"So if you have a situation where you have dynamics of a viral spread in a community, it's less likely that the children who are in the school -- if we do things right, it's less likely that they're going to get infected," he said. "Obviously we want to get the teachers vaccinated, we want to make sure they have the resources to do it correctly. But when you look at the history of how this virus is moving in schools, it seems to be less spreading there than it is in the community."

Fauci also expressed concern over the new, more contagious variant of the novel coronavirus that was first identified in South Africa and has since spread to dozens of other nations, including the United States.

"The one in South Africa, George, troubles me," he said, explaining that lab experiments show the neutralizing antibodies induced by existing COVID-19 vaccines are "diminished by multifold" when tested against the South Africa variant, called B1351.

"It's still within the range of what you would predict to be protective," he added, "but I take no great comfort in that."

However, scientists are already working on vaccines that will specifically target the South Africa strain, according to Fauci.

"May not be necessary," he said, "but if it is we'll already be on the road to be able to give people a boost that directs against the South African isolate."

Being vaccinated against COVID-19 will not be a requirement to compete in the upcoming Tokyo Olympics, organizers said Thursday.

The 2020 Summer Olympics were supposed to kick off in the Japanese capital last year on July 24. But in late March, amid mounting calls to delay or cancel the upcoming Games, the International Olympic Committee (IOC) and Japan’s prime minister announced that the event would be held a year later due to the coronavirus pandemic.

The Games are now scheduled to open in Tokyo this summer on July 23, but doubt has surfaced as Japan — and much of the world — grapples with a resurgence of COVID-19 infections. Moreover, Japan is not expected to begin administering its first round of COVID-19 vaccinations until the end of February.

During a press briefing Thursday following a call with the IOC's president, organizers were asked how Japan will safely host the Olympics as scheduled when the country's mass vaccination campaign is not expected to inoculate most of the population by that date.

"Since last year, we have been having thorough debates and discussions on that topic. We do not consider the vaccine as a prerequisite," Toshiro Muto, chief executive officer of the Tokyo 2020 organizing committee, told reporters. "Of course, it's desirable to have as many people as possible vaccinated, and that would bring about positive benefit. But even if vaccination is not done, we will be able to hold the Games."

Muto added that COVID-19 vaccinations would be administered to athletes but it wouldn't be an obligation.

As for vaccinating staff and volunteers, Muto said that decision will be made at the national government level.

Yoshiro Mori, president of the Tokyo 2020 organizing committee, said they are still considering holding the Games without spectators.

“One option among many would be to hold the games without spectators," he told reporters. "We don’t want to do this but we must take this scenario into consideration."

With less than six months left until the opening day, a recent poll by Japanese news agency Kyodo found that around 80% of people in Japan believe the Tokyo Olympics should not be held this summer. When asked by ABC News about that opinion, Mori said: "There is a balance. On one hand there is criticism, the other hand is support."

Mori noted that the IOC's president has "strongly backed up our efforts" to hold the Tokyo Olympics as planned.

"Nowhere did we hear objections or doubt," he told reporters. "Everyone wants to successful hold the games."

ABC News' Anthony Trotter and Karson Yiu contributed to this report.

British Prime Minister Boris Johnson has indicated that England's lockdown restrictions will remain in place until at least early March.

In a statement to lawmakers at the U.K. House of Commons on Wednesday, Johnson said officials "do not yet have enough data to know exactly how soon it will be safe to reopen our society and economy." But he expressed hope that schools could reopen from March 8, so long as his government meets its target of vaccinating everyone in the top four priority groups by mid-February.

The prime minister also announced new restrictions for travelers arriving in England from countries deemed to be high-risk. He said the United Kingdom remains in a "perilous situation" with more than 37,000 people hospitalized with COVID-19 -- almost double the amount during the previous peak in April.

During a press conference later Wednesday, Johnson told reporters that March 8 was the "earliest" date by which the government could "responsibly" allow schoolchildren to return to classrooms.

The comments come after the U.K. became the fifth country in the world to record more than 100,000 deaths from COVID-19.

England entered its third national lockdown of the coronavirus pandemic on Jan. 5.

Although Johnson is the prime minister of the U.K., his administration is only responsible for COVID-19 restrictions in England because public health legislation is devolved to national governments within the U.K., meaning that Scotland, Wales and Northern Ireland are responsible for their own coronavirus-related policies.