An international team of 13 scientists researching the origins of COVID-19 arrived Thursday in Wuhan, China, where the novel coronavirus was first discovered, according to the World Health Organization.

"The experts will begin their work immediately during the 2 weeks quarantine protocol for international travelers," the WHO wrote on Twitter.

All team members had to be tested for COVID-19 again in Singapore before flying to China. The polymerase chain reaction (PCR) tests were all negative, but two IgM antibody tests returned positive results. Those two scientists remain in Singapore as they are retested, according to the WHO.

A total of 965,000 workers in the United States filed jobless claims last week, the U.S. Department of Labor said Thursday, an increase of 181,000 from the prior week.

The Labor Department also said that more than 18 million people were still receiving some form of unemployment benefits through all government programs for the week ending Dec. 26. For the comparable week in 2019, that figure was just above 2 million.

The weekly unemployment tally has fallen since peaking at 6.9 million in March but still remains elevated by historical standards.

The pre-pandemic record for weekly unemployment filings was 695,000 in 1982.

That record has been broken every week since late March.

As of last month, the unemployment rate in the U.S. was 6.7%. It was 3.5% last February.

-ABC News’ Catherine Thorbecke contributed to this report

This week’s national ensemble forecast released by the U.S. Centers for Disease Control and Prevention predicts that 16,200 to 29,600 more Americans will likely die from COVID-19 in the week ending Feb. 2.

The national ensemble estimates a total of 440,000 to 477,000 deaths from the disease will be reported nationwide by that date.

Nearly all U.S. metro areas with over 500,000 people are in "full resurgence" of COVID-19, the White House coronavirus task force said in its latest report, obtained by ABC News Wednesday.

In the report, dated Jan. 10, the task force said the fall/winter surge has had nearly twice the rate of rise in COVID-19 cases as the spring and summer surges.

Several states, including Arizona, California, Florida, Georgia, Louisiana, New Mexico and South Carolina, are also in "full pandemic resurgence," the report stated.

Only "aggressive mitigation" can "match a more aggressive virus," and Americans must take more precautions, "moving beyond what worked in the summer to more layered mitigation," the report stated.

The task force recommended uniform mask implementation and "strict physical distancing." Without that, "epidemics could quickly worsen as more transmissible variants spread and become predominant," it warned.

ABC News' Josh Margolin and Brian Hartman contributed to this report.

Seychelles, an island nation of just under 100,000 people, has begun immunizing its population against COVID-19 with a vaccine developed by China’s state-owned pharmaceutical company, Sinopharm.

Seychelles President Wavel Ramkalawan became the first African head of state to receive the Sinopharm vaccine on Sunday, as the country officially launched a national COVID-19 immunization campaign -- the first in Africa to do so. The Seychelles Ministry of Health began administering the shot to priority groups on Monday, starting with health care professionals and other front-line workers, according to a press release from the president’s office.

Last month, China authorized Sinopharm's vaccine for general use after the company announced that preliminary data from late-stage trials had shown it to be 79.3% effective. The shot is administered in two doses.

The United Arab Emirates donated 50,000 doses of the Sinopharm vaccine to Seychelles. India offered 100,000 doses of another COVID-19 vaccine developed by England’s University of Oxford and British-Swedish pharmaceutical giant AstraZeneca, which are due to arrive in Seychelles at the end of the month, according to the president's office.

“With such a robust vaccination campaign, Seychelles aims to be the first country in the world to vaccinate at least 70% of its over 18 population,” Ramkalawan said in a statement Sunday. “From there, we will be able to declare Seychelles as being COVID safe. This will allow us to reopen our economy.”

Seychelles, an Indian Ocean archipelago located off the coast of East Africa, has reported 508 confirmed cases of COVID-19 since the start of the pandemic, including at least one death, according to the latest data from the Africa Centers for Disease Control and Prevention.