South Korea on Tuesday reported its first two cases of the new Delta Plus COVID-19 variant.
One of the confirmed patients was a man in his 40s who had no recent travel records.
Test results in people who were in close contact with the man showed that only one family member tested positive.
However, it's not been stated whether that family member was also infected with the Delta Plus.
The second case was found in an overseas traveler.
Health officials are now carrying out investigations.
"We are looking into the case to identify the route of transmission. So far, except for one family member, there are no additional confirmed cases tied to this."
The new variant, Delta Plus is similar to the Delta variant but with an extra mutation, known as K417N, in the spike protein of the virus.
This mutation is also found in the Beta and Gamma variants.
So far, cases of the Delta Plus have been reported in only a handful of countries, including the U.S., UK and India.
While further studies are needed to understand how virulent this new strain is, medical experts say that the Delta Plus could be more transmissible and more infectious.
"Delta Plus means that Delta variant has another variant in the spike protein. So the spike protein of the Delta Plus virus has three different mutants in it. So that means may be it is more transmissible or it is more virulent compared to the Delta virus."
Some have even raised concern that the Delta Plus could reduce the efficacy of vaccines currently in use.
That's because the Delta variant has somewhat appeared to be resistant to vaccines and the new Delta Plus variant is expected to show similar effects.
Studies are underway to test how effective COVID-19 vaccines are against this new strain.
Min Suk-hyen, Arirang News.