Despite ongoing slowdowns in the decline of new cases or even sporadic increases, Korea’s Covid-19 spread has been on a decreasing trend recently, albeit with one exception – the under-18 group.
According to Central Disaster and Safety Countermeasures Headquarters (CDSCH) on Tuesday, the number of confirmed cases among those 18 or younger stood at 1,687, accounting for 21.4 percent of the total 49,933 new cases, meaning more than one in every five new infections came from this age group.
Since last Wednesday, the share of the under-18 group has ranged from 18.3 percent to 23.6 percent. The proportion of patients under 18 rose as the decline of new Covid-19 cases stagnated over the weekend. The quarantine authorities believe that the recent slowdown in the number of confirmed cases was due to increased activity during Children's Day over the weekend.
"The incidence rate increased in all age groups, but the highest rise was in teens," a CDSCH official said. "Infections have increased among the young, active population."
In addition to the stagnant decrease in the number of daily confirmed cases, health officials said they had confirmed five additional BA.2.12.1 cases, raising the total to six in Korea.
All six cases came from travelers coming from the U.S.
The quarantine authorities said they are conducting epidemiological investigations on 14 close contacts but have confirmed no additional transmission cases yet.
BA.2.12.1, which is spreading in the U.S., is a sub-phylogenetic variant from BA.2. First detected in the U.S. in December, the variant has spread to at least 15 countries, including Singapore, which confirmed two cases.
According to health officials, while the stealth Omicron variant has about 30 percent higher propagation power than the existing Omicron, the BA.2.12.1 is estimated to show a 23-27 percent faster detection increase rate than the stealth Omicron.
Authorities explained that BA.2.12.1 has two more amino acid mutations than the 29 amino acid mutations of the stealth Omicron may have affected the subvariant's transmission power and immune evasion.
The quarantine authorities are judging that the risk of new mutations in the Omicron variant is not yet high.
"We do not expect the impact on recombinant mutations to be significant," said Lee Lee Sang-won, head of the epidemiological investigation and analysis team at the headquarters. “None of the recombinant mutations have shown signs of becoming a dominant strain."
Although the government is keeping a close watch on the possible influx of B4 and B5 mutations discovered in South Africa, health officials believe that the risk is low because the epidemic area is concentrated in only certain parts of the globe, Lee added.
Lee also explained that although the spread of the BA.2.12.1 mutation, rapidly increasing in the U.S. and other countries, is the most problematic, this mutation does not appear to be a risk factor that increases the severity or mortality.
On Tuesday, the KDCA confirmed 49,933 new virus cases, raising the cumulative caseload to 17,614,895.
The death toll came to 23,462, up 62 from the previous day, with a fatality rate of 0.13 percent. However, critically ill patients came to 398, down 23 from a day earlier.
About 33.19 million people have received booster shots or 64.7 percent of the country's population. The number of fully vaccinated people also came to 44.56 million, representing 86.8 percent of Koreans, the KDCA said.