Proof of vaccination against coronavirus will be required to enter city bars, restaurants, gyms, theaters and sports venues under a new mandate announced by Mayor Michelle Wu during a raucous press conference. “Vaccination is the most powerful tool we have to fight this pandemic,” said Wu Monday, announcing the city’s new rules as protesters flowed inside shouting “USA, USA!” In addition, all city workers will be required to get the vaccine if they want to keep their jobs, Wu said. Workers must have at least one dose by Jan. 15 and two doses by Feb. 15. The new, stricter requirement...