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SEOUL, Jan. 13 (Yonhap) -- South Korea's daily coronavirus cases stayed above 4,000 for the second consecutive day Thursday, deepening concerns over a possible resurgence amid the continued spread of the omicron variant.
The country added 4,167 new COVID-19 infections, including 3,776 local infections, raising the total caseload to 679,030, according to the Korea Disease Control and Prevention Agency (KDCA).
Thursday's tally is down from 4,385 the previous day, when the figure bounced back to 4,000 from the 3,000 level in about a week.
The number of imported cases hit an all-time high of 391 on Thursday, beating the previous record of 380 logged the previous day, amid the fast spread of the variant in the world, according to the KDCA.
Of the imported cases, 67.8 percent were from the United States. The authorities called for extra caution on those who attended the Consumer Electronics Show (CES) in Las Vegas last week, as some 70 attendees had tested positive for COVID-19 as of Wednesday and contact tracing is still under way.
To stem the inflow of the omicron variant from overseas, the health authorities are reviewing comprehensive countermeasures, including toughening rules on the proof of negative test results for incomers, the KDCA said.
The country reported 44 more COVID-19 deaths, raising the death toll to 6,210, according to the health authorities. The fatality rate came to 0.91 percent.
The number of critically ill COVID-19 patients stood at 701, staying below 800 for the fourth straight day, the KDCA said.
Later in the day, the first batch of U.S. drug giant Pfizer Inc.'s Paxlovid antiviral COVID-19 treatment pills will arrive in South Korea, according to the public health authorities.
The oral pills for 21,000 people will begin being administered Friday to patients with a compromised immune system and those aged over 65, with the second batch for 10,000 people to be shipped by the end of this month, they added.
South Korea has secured Pfizer's medication for 762,000 people, as well as oral pills made by U.S. drugmaker's MSD for 242,000 people.
As of Thursday, 43.3 million people, or 84.4 percent of the country's 52 million population, have been fully vaccinated, and 22.1 million, or 43.1 percent, have received booster shots, the health authorities said.
On Wednesday, South Korea also authorized the use of U.S.-based biotechnology company Novavax Inc.'s COVID-19 vaccine, which is expected to be used as early as next month. The authorities said this "classic" type of vaccine could encourage more unvaccinated people to consider getting a shot and further boost the country's overall vaccination rate.
The virus situation has showed signs of slowing down in recent weeks thanks to the tightened antivirus restrictions and the active campaign for booster shots, but the health authorities have remained vigilant due to the fast spread of the omicron variant.
About 12.5 percent of the country's locally transmitted cases reported last week were found to have been caused by the omicron variant, but the figure will likely grow to over 50 percent, the official said, adding that the spread of the variant would push up the number of total infections to become a starting point of the fifth wave of the pandemic.
More than 80 percent of the imported cases reported last week were found to have been infected with the omicron variant on average, according to the KDCA.
The government plans to announce its decision Friday on whether to extend the current social distancing rules, which went into effect in mid-December in the wake of a drastic surge in infections and will expire Sunday.
Some have raised the possibility of the rules being relaxed, but officials say the current curbs are likely to be extended for at least two weeks, citing concerns over an uptick around the Lunar New Year holiday later this month.
Of the locally transmitted cases, 66.9 percent were from the metropolitan region. Seoul reported 868, and the surrounding Gyeonggi Province and the city of Incheon, west of Seoul, added 1,444 and 224 new cases, respectively.