Scientists worry the mutation, coupled with other existing features of Delta variant, could make it more transmissible.
South Korea has posted a sharp increase in its coronavirus cases as it struggled to tame its fourth wave of infections amid the spread of new coronavirus variants strains.
The Korea Disease Control and Prevention Agency (KDCA) reported 1,725 cases for Tuesday, up by more than 500 from the day before, as more tests were conducted after the weekend.
Total infections rose to 203,926, with 2,106 deaths.
On Tuesday, the KDCA said it had detected South Korea’s first two cases of the new Delta Plus COVID-19 variant, a sub-lineage of the Delta variant first identified in India.
The daily tally hit a new high of 1,895 last week, partly fuelled by the more contagious Delta variant, with the fourth COVID-19 wave showing little signs of subsiding.
Health authorities were concerned that people travelled about 6.4 percent more last week compared with the week before – or about 34 percent more than in early January, in the regions beyond the capital Seoul and its neighbouring areas – largely for summer vacations.
“The movements in those regions have been increasing for three consecutive weeks,” senior health official Lee Gi-il told a briefing.
“There is fatigue from long periods of distancing, and it’s a summer vacation season.”
The government tightened social distancing curbs last week across most of the country for two weeks before the peak summer holiday period.
The Delta Plus variant is a sub-lineage of the Delta variant first identified in India, and has acquired the spike protein mutation called K417N, which is also found in the Beta variant first identified in South Africa.
Only a handful of countries, including the United Kingdom, Portugal and India, have reported Delta Plus cases so far.
Delta Plus is still being studied, but some scientists have said it may be more transmissible.
Health authorities have said several major vaccines work against the Delta variant.
Some 39.3 percent of South Korea’s 52 million population have received at least one shot as of Wednesday, while 14.2 percent have been fully vaccinated, KDCA data showed.