(ATTN: RECASTS headline, lead; UPDATES with more info throughout)
By Kim Han-joo
SEOUL, Aug. 3 (Yonhap) -- South Korea has confirmed 2,109 more cases of four major contagious variants of the new coronavirus over the past week, including 1,928 cases of the highly transmissible delta variant, health authorities said Tuesday.
The caseload of such infections reached 8,125 here, with the number of delta cases first reported in India tallied at 4,912, according to the Korea Disease Control and Prevention Agency (KDCA).
Health authorities said the country will witness more cases of the variants down the road.
The rate of variant cases detected through gene analysis came to 67.6 percent over the past week, sharply up from 54.8 percent a week earlier, the KDCA said.
Earlier in the day, the KDCA said the country confirmed two cases of the highly transmissible delta plus variant of the novel coronavirus.
It marks the first time the country has reported cases of the delta plus version, considered a sublineage of the delta variant, the KDCA said.
The KDCA said one of the delta plus cases is a man in his 40s who has never been overseas.
The delta variant of the novel coronavirus was first detected in India last October. The "subvariant" strain is considered to be even more contagious, possibly capable of infecting people even after inoculation.
The only known difference with the delta variant is an additional mutation called K417N -- a spike protein that allows infection of healthy cells.
The "subvariant" strain has been identified in over 20 countries, indicating that more study is needed to understand the extent of the transmission, the authorities said.
The steady rise in variant cases poses a threat to the country's virus battle currently dogged by a spike in new cases and the slowdown of its inoculation campaign.
On Tuesday, the country reported 1,202 new COVID-19 cases, staying in the 1,200s for the second day in a row, due to fewer tests.
Slightly over 20 million people have been inoculated as of Tuesday since the country started its nationwide vaccination program in late February
To block the inflow of the new emerging strain from India, entrants from the country are mandatorily quarantined at state facilities for seven days before being put under self-quarantine, depending on the results of virus tests.