A pedestrian passes a mobile vaccine clinic in the Brooklyn borough of New York, United States, on Aug. 23, 2021. (Photo by Michael Nagle/Xinhua)

The newly-discovered Omicron variant of COVID-19 in South Africa has raised fears about the global trajectory of the pandemic, while some countries including the United States have raced to impose travel restrictions on southern African countries.

On Friday, U.S. President Joe Biden announced that his country will impose travel restrictions on eight African countries including South Africa, Botswana, Zimbabwe, Namibia, Lesotho, Eswatini, Mozambique and Malawi as the new coronavirus variant was detected on the continent.

Except for this "precautionary" measure, Biden again urged Americans and people around the world to get vaccinated against the virus.

Australia and Japan were among the latest countries on Saturday to either halt flights to the region or announce mandatory quarantines and screenings.

The World Health Organization (WHO) said there was preliminary evidence that the variant, which it named Omicron after the Greek letter, was more transmissible than the Delta variant that is currently dominant world-wide, and other virus strains. Meanwhile, Belgium, Israel and Botswana also detected first cases of the new variant.

"Although scientists were still figuring out the exact effects of the variant's many mutations, its discovery highlights the continued threat posed by an evolving virus to the world's emergence from the pandemic," reported The Wall Street Journal on Friday.

U.S. officials have spoken with scientists and leaders in South Africa to learn more about Omicron. The Centers for Disease Control and Prevention (CDC) said on Friday that Omicron hadn't been identified in the United States, while U.S. stock markets sold off, with the Dow Jones Industrial Average suffering its worst day in a year.

CHILLING EFFECT

The WHO labeled Omicron a "variant of concern," a designation given to variants like Delta that require close scrutiny from public health officials. Preliminary evidence suggested that Omicron may increase the risk of reinfection relative to other variants of concern.

South African researchers identified the first Omicron case on Nov. 9, then reported the variant to the WHO on Wednesday. Scientists are hopeful that they spotted the variant early, since the majority of known cases are still concentrated in southern Africa.

"Scientists are still waiting on lab studies to determine how well coronavirus antibodies -- either from natural infection or vaccines -- hold up against Omicron. They're also watching carefully to see how quickly the variant spreads across the globe, particularly in countries with higher vaccination rates," reported Business Insider on Saturday.

Moderna, BioNTech-Pfizer and Johnson & Johnson all said that they're testing how well their vaccines protect against Omicron.

Merck said on Friday in a final analysis of a clinical trial, its antiviral pill reduced the risk of hospitalization and death among high-risk COVID-19 patients by 30 percent, down from an earlier estimate of 50 percent.

"News of the Omicron variant, which has an unusually high number of mutations, will certainly throw a spanner in the works for the Biden administration as the president struggles with flagging approval ratings and a pessimistic view of the economy," reported CNN on Friday. "The administration will need to work quickly to get ahead of the new variant."

The pandemic is far from over, and after nearly two years and more than 775,000 deaths, many Americans are traumatized and on edge, said the television network, adding that with the variants stymying hopes of a full recovery, "it has become increasingly difficult to embrace any good news, as fear and uncertainty continue to dictate so much of our lives."