COVID Vaccine Maker Moderna Flags Japan Ambition With Sumo Sponsorship

A sign marks the headquarters of Moderna Therapeutics, which is developing a vaccine against the coronavirus disease (COVID-19), in Cambridge, Mass., on May 18, 2020. Brian Snyder/Reuters

TOKYO—Moderna Inc. is sponsoring sumo flags in its first such promotion in Japan, as the COVID-19 vaccine maker seeks to wrestle market share from compatriot Pfizer Inc.

The U.S. firm’s introduction to the broader Japanese public was set back after some of its doses last year were found to be contaminated, although it has clawed back market share since with the help of a government-endorsed programme.