The National Institute of Infectious Diseases in Tokyo’s Shinjuku Ward (Asahi Shimbun file photo) Health officials have confirmed Japan now has many cases of a new variant of the novel coronavirus that could make currently available COVID-19 vaccines less effective. The mutated strain of the virus was detected in 91 patients in the Kanto region, with two more confirmed infected with the variant at airport quarantine checks, according to the National Institute of Infectious Diseases (NIID). Tokyo Medical and Dental University on Feb. 18 also reported three cases of the variant in the capital. “The variant could pose a risk to efforts to contain the spread of infections in the mid- to long-term,” an NIID official said.