A new coronavirus variant has been detected in four travelers from Brazil’s Amazonas state, Japan’s health ministry said Sunday. The strain differs from highly infectious variants first found in Britain and South Africa that have driven a surge in cases in those countries. A ministry official said studies were underway into the efficacy of vaccines against the new variant. “At the moment, there is no proof showing the new variant found in those from Brazil is high in infectiousness,” Takaji Wakita, head of the National Institute of Infectious Diseases (NIID), told a health ministry briefing. Still, Brazil’s Health Ministry said it has been notified by Japanese authorities that the new variant has 12 mutations, one of which is also present in the variants found in the U.K. and South Africa. “It implies a potential higher virus infectiousness,” it said. Of the four travelers who arrived at Tokyo’s Haneda Airport on Jan. 2, a man in his 40s had a problem breathing, a woman in her 30s had a headache and sore throat and a teenage male had a fever, while a teenage girl showed no symptoms, the health ministry said. 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 in three different people who had close contact with a man infected with the strain. Brazil’s Health Ministry asked the Japanese government to provide information on the new variant of the novel coronavirus detected in the four travelers. The ministry asked for information such as the genetic sequence of the new strain. The Brazilian ministry has taken necessary preventive measures including sending a cautionary notice to related domestic organizations, an official said. It has asked the Japanese ministry about information on the travelers’ stays in Brazil in order to track their possible contact with others, the official said. Brazil is experiencing a second wave of coronavirus infections, with a daily average of more than 50,000 people testing positive for the virus in January. In Brazil, the mutant strains of the British and South African types have been confirmed. In Japan, the government declared a state of emergency for Tokyo and three neighboring prefectures last week after seeing a steep rise in coronavirus cases,. Cumulative cases nationwide have reached about 289,000, with 4,067 deaths as of Sunday, public broadcaster NHK said. Source