South Korea's daily new coronavirus cases stayed in the 400s for the second consecutive day Thursday as the country pushes forward with its vaccination drive amid looming safety concerns.

The country reported 424 more COVID-19 cases, including 401 local infections, raising the total caseload to 91,240, the Korea Disease Control and Prevention Agency (KDCA) said.

The tally was slightly down from the 444 recorded the previous day.

The country added seven more deaths from COVID-19, raising the total to 1,619. The fatality rate was 1.77 percent.

South Korea reported more than 1,000 daily cases in late December before it saw a downward trend. The daily tally has been hovering around 300 and 400 recently.

The country has administered vaccinations to a total of 154,421 people since launching a mass vaccination campaign last Friday, with an additional 65,446 getting the shots Wednesday, according to the KDCA.

AstraZeneca's vaccine accounted for 151,679, while Pfizer's took up 2,742.

The vaccination campaign is expected to pick up pace as more people in COVID-19 vaccination priority groups, including medical workers and patients at nursing homes, get the shots down the road.

The country aims to achieve herd immunity by November.

A total of 718 cases of side effects after vaccinations have been reported so far, up 511 from the previous day, with 709 of them just suffering mild symptoms like headache.

An additional four suspected cases of anaphylactoid reaction, which has similar symptoms to anaphylaxis, a serious allergic reaction after immunization, have been reported, raising the total of such cases to seven. But health authorities said they have yet to find a causal relationship between the vaccinations and such adverse events.

Health authorities said they are looking into two cases of deaths after vaccination, adding that a causal relationship between the vaccinations and the deaths will be investigated. They added three more people died after getting vaccinated and that epidemiological investigation is also under way.

To stem further spread of the new coronavirus, the country extended its social distancing rules, including bans of private gatherings of five or people, through March 14.

The greater Seoul area, home to about half of the nation's 52 million population, is under Level 2, the third highest in its five-tier system, and other regions are placed under Level 1.5.

Health authorities are also closely monitoring the spread of more contagious COVID-19 variants. As of Thursday, the country had confirmed 162 such cases since confirming the first variant case in October, with six of them being identified this week.

Of them, 138 were the Britain variant, followed by the South African strain with 18 and the Brazilian strain with six.

Of the locally transmitted cases, 117 additional cases were reported in Seoul and 177 in Gyeonggi Province that surrounds the capital. Incheon, 40 kilometers west of Seoul, identified 18 new cases.

Among virus clusters, a restaurant in southwest Seoul added six more cases, raising the total to 34. Cluster infections involving foreign workers in Dongducheon, just north of Seoul, increased by seven to 103.

A savings bank in Seongnam, south of Seoul, reported eight additional cases, increasing the related caseload to 27.

The number of cases linked to a nursing home in Yongin, south of Seoul, rose by two to 61. The number of cases tied to a vessel in Busan reached 18 after it reported five more cases.

There were an additional 23 imported cases, up five from a day earlier, increasing the total caseload to 7,129. Of the new imported cases, five were from the United States followed by Hungary and Mexico with three.

The number of seriously or critically ill COVID-19 patients was 140, up 11 from the previous day.

The total number of people released from quarantine after making full recoveries was 82,162, up 462 from a day earlier, with 7,459 people being isolated for COVID-19 treatment, down 45 from a day ago.

South Korea has carried out 6,751,900 COVID-19 tests, including 35,697 from the previous day. (Yonhap)