TOKYO: Another new variant of the novel coronavirus has been found in Japan, the health ministry said Sunday.

The new variant, which partially has the same mutation as that of different variants reported in Britain and South Africa, was detected in four people who arrived at Tokyo International Airport at Haneda from Brazil on Jan. 2, it said.

With no information available on the transmissibility of the newly found variant, whether it could cause severe symptoms and possible impacts on the effectiveness of vaccines, the National Institute of Infectious Diseases and others are conducting detailed research on the virus strain.

Of the four people, a man in his 40s showed no symptoms upon arrival, but later developed breathing difficulties and was hospitalized, the ministry said. A woman in her 30 has symptoms such as headache. A man in the age group of 10-19 has a fever, while a woman in the same age group is free of symptoms.

The four people tested positive for the novel coronavirus in airport quarantine, and the new mutant strain was detected through a detailed examination by the NIID, according to the ministry.

The ministry also said that the variant reported in Britain has been found from three different people who had close contact with a man infected with the variant.