South Korea's daily new coronavirus cases rebounded to over 700 on Wednesday, the most in over three months, as health authorities are looking at the option of raising social distancing rules to contain the virus resurgence.

The country reported 731 more COVID-19 cases, including 714 local infections, raising the total caseload to 111,419, the Korea Disease Control and Prevention Agency (KDCA) said.

Wednesday's daily caseload was the highest since Jan. 7, when 869 new cases were confirmed. The number of new cases remained in the 500s over the last two days due largely to fewer tests conducted over the weekend.

The country added seven more deaths, raising the total to 1,782.

Health authorities worried over a fourth wave of the pandemic in spring, warning of stronger restrictions on multiuse facilities if the virus transmissions show no signs of letup.

"We will consider adjusting the social distancing schemes and measures on business operation hours after closely monitoring this week's situations," Yoon Tae-ho, a senior health official, said in a briefing.

Last week, South Korea decided to maintain the current level of social distancing rules through May 2 to contain the virus, while banning operations of entertainment establishments in the greater Seoul area and the southeastern port city of Busan.

The greater Seoul area, home to half of the nation's 52 million population, is under the Level 2 distancing scheme, the third highest in the five-phase system. The rest of the country is under Level 1.5, except for some municipalities that have adopted Level 2 measures.

Restaurants in the capital area are allowed to have dine-in customers until 10 p.m. under the current guidelines, but officials said they could shorten their business hours if daily cases rise further.

The nationwide traffic volume stood at 71 million over the weekend, up 14.6 percent from a week earlier, which is similar to the level in November when the third wave of pandemic began, Yoon said.

"This seems to be more evidence that people have let their guard down," Yoon said. "People could become relaxed, but the COVID-19 virus doesn't. The virus is tireless and indiscriminate."

The number of locally transmitted cases surpassed 600 over the past week for the first time in three months, and the proportion of untraceable virus cases stood at 28.2 percent during the period, the KDCA said.

Health Minister Kwon Deok-cheol vowed to expand preemptive testing to detect patients at an early stage and explore ways to effectively use self-testing kits to further step up the testing capacity.

The Seoul metropolitan government is pushing to introduce rapid COVID-19 self-testing kits in schools, universities and religious facilities as part of its new campaign to safely reopen the city.

Under new Mayor Oh Se-hoon, the city government has been working on a coronavirus response scheme tailored to the needs of individual businesses, raising concerns about potential inconsistencies with the policies of the central government.

Since the country started its vaccination program on Feb. 26, a total of 1,239,065 people, or 2.38 percent of total population, have been given COVID-19 vaccine shots, including 43,489 the previous day.

AstraZeneca's vaccine has been given to 936,448 people, while 302,618 received that of Pfizer.

The KDCA said 60,567 people have received two doses.

A total of 11,799 cases of side effects after vaccinations have been reported, up 64 from a day earlier, but 98.4 percent were mild symptoms, including muscle pain and fever.

Another death after vaccinations was reported, raising the total to 49, according to the KDCA. Authorities, however, said most cases were not related to the vaccination.

South Korea plans to vaccinate 12 million people by the end of June, with a goal of achieving herd immunity by November.

Health authorities resumed administering AstraZeneca vaccines to eligible recipients aged over 30 on Monday, days after putting the program on hold amid growing concerns over its safety.

With only two types of vaccines currently available here, the health ministry said it expects to secure Novavax vaccines as early as June, and 20 million doses will be ready by the third quarter. Novavax vaccines require two shots for immunization.

In regard to the vaccine from Johnson & Johnson, whose use was suspended in the United States over rare blood clotting, the health authority said the country has not yet changed its plan to secure the one-shot dose vaccine and has been consulting with the US drugmaker on its procurement schedule.

"We will continue to conduct safety reviews while monitoring (the US situation)," Baek Young-ha, who is in charge of the vaccine procurement program, said in a briefing.

The country signed a contract with Janssen for 6 million doses for its vaccine rollout, which was initially expected to be provided in the third quarter.

Of the newly confirmed locally transmitted cases, 245 came from Seoul, with Gyeonggi Province that surrounds the capital city accounting for 238.

The southeastern port city of Busan reported 48 new cases.

There were 17 additional imported cases, adding three from the previous day.

The number of seriously or critically ill COVID-19 patients was 100, down one from Tuesday

The total number of people released from quarantine after making full recoveries was 101,938, up 651 from a day earlier. (Yonhap)