Ten days into the toughest level of distancing curbs in Greater Seoul, the nation has continued to see record-breaking daily case numbers. The current restrictions that end Sunday are likely to be extended to curb further spread.

As of Wednesday at midnight, the number of new daily confirmed cases reached a record high of 1,842 people. The figure includes 270 infected sailors of the 301-strong Cheonghae unit on an anti-piracy mission in waters off Africa.

Of the newly confirmed cases, 1,533 were locally transmitted, with 987 from Greater Seoul. That includes 494 in Seoul, 363 in Gyeonggi Province and 130 in Incheon. There were also 102 cases in Busan.

Among the 309 imported cases of coronavirus, 284 were Koreans.

As the pandemic continues to rage, experts say the nation should extend the period of the highest level of the four-tier distancing measures, which began on July 12 and is set to end Sunday.

Eom Joong-sik, a professor at Gachon University Gil Hospital, said if the nation lowers the level next week, the confirmed number of cases will surge immediately.

Eom said it is too early to see the effect of the toughest level of curbs in the Seoul area because of the holiday season. “The number of confirmed cases will be on the decline only after at least four weeks (of implementing Level 4 rules).”

The social distancing policy advisory body also put weight on the need for an extension during its meeting Wednesday night.

At the meeting, opinions were gathered on extending the Level 4 distancing rules in the Seoul metropolitan area for two more weeks.

The government plans to discuss measures with related ministries and local governments based on the opinions of the advisory body and confirm new distancing rules by Sunday at the latest.

The nation’s vaccination efforts are also continuing.

Authorities said that as of Wednesday midnight, 139,214 people had been newly inoculated and a total of 16.58 million people had received their first dose, constituting 32.2 percent of the nation’s total population.

The daily number of those fully vaccinated rose by 23,000 to reach 6.72 million people, or 13.1 percent of the population.

From Monday, people aged 55 to 59 are to begin to receive their first shots. The inoculation period is about three weeks, until Aug. 14. The number of people in this age group is about 3.56 million, and 82.5 percent of those have already made reservations.

Online reservations for people aged 50 to 54, who will be inoculated from Aug. 16-28, are also being made now.

Despite the efforts underway, breakthrough infections, while rare, are creeping up.

Breakthrough infections refer to cases in which people test positive for the coronavirus at least 14 days after they have been fully vaccinated.

As of Wednesday, 647 people out of 5.4 million fully vaccinated individuals had tested positive. Although this is merely 0.01 percent, the figure has more than doubled in 11 days.

By vaccine, Johnson & Johnson’s Janssen had the largest number of such cases with 364, followed by Pfizer with 145 and AstraZeneca with 148.

Quarantine authorities and experts say it is an unusual phenomenon and the incidence rate per 100,000 inoculations is only 12.