Two cases of the new Delta plus variant have been recorded this week in South Korea. It was found in a man in his 40s with no recent travel records.

Reports from South Korea claim that 280 people were in contact with the man and only one of them, his son, tested positive for the coronavirus. The second person to test positive for the Delta plus was found in a traveler who returned from the U.S.

The Delta plus variant had first been identified in India and has acquired a spike protein mutation called K417N, which has been found in the Beta variant first identified in South Africa. The Delta plus has also been identified in Europe by Public Health England. Some scientists say the Delta plus is more transmissible and studies are ongoing globally to test the effectiveness of the vaccine against the new mutation.

The Delta plus strain has been listed as a “variant of concern” by the World Health Organization. The Indian Health Ministry said the variant could bind more easily to lung cells and could be resistant to therapies.

“We got to be more willing to consider observations made in other countries dealing with the coronavirus,” said James Hildreth, president and chief executive at Meharry Medical College.

“We saw what happened with the Delta in India and how quickly it spread, why wouldn’t we think the Delta plus would be any different,” Hildreth said.

“We must remain watchful, new variants in particular, notably the Delta variant, mean we must be cautious,” said German Chancellor Angela Merkel.

According to Public Health of England, at least 39 cases of the Delta plus have been found in the U.K., where 72% of adults have been vaccinated.

Colin Angus, a public health modeler and analyst, said the Delta plus variant has mostly been found in younger people but data show that antibodies from vaccinated people are effective against the emerging variant.

Richard Novak, head of the division of infectious diseases at the University of Illinois Health, said it’s too early to say if the Delta plus could evade vaccines or is more infectious than the original strand of coronavirus.

“This is a process of natural selection and selecting viruses that are more contagious. All viruses want to do is reproduce themselves. The ones that do become the dominant virus, we’re going to see other variants, the variants will get more efficient as time goes on,” Novak said.