China imposed a partial shutdown on the 1.3 million residents of Yuzhou, a city in the central province of Henan, after finding three asymptomatic cases of Covid-19. Hong Kong also pursued the Covid-zero strategy, hunting for six people who may have been part of a cluster of omicron infections. New York City may expand its vaccine mandates to require boosters. A third shot of Pfizer Inc.’s vaccine for 12- to 15-year-olds won emergency approval from U.S. regulators. U.K Prime Minister Boris Johnson warned that the pandemic is far from over. Russia reported the lowest number of cases since June, while Germany began weighing new measures in the face of rising infections. Key Developments: Virus Tracker: Cases pass 291 million; deaths exceed 5.4 million Vaccine Tracker: More than 9.2 billion shots administered Omicron’s mild infections hint at less-severe phase of pandemic […]