(AP) — A COVID-19 vaccine requirement for teachers and other staff members has taken effect in New York City’s million-plus-student public school system. The city had planned to bring in substitutes on Monday, with Mayor Bill de Blasio warning that unvaccinated school employees would be placed on unpaid leave. De Blasio said 95% of the city’s roughly 148,000 public school staffers had received at least one vaccine dose as of Monday morning. The nation’s largest school system is one of the first in the country to require inoculations for all its staffers. A similar mandate is set to go into effect in Los Angeles on Oct. 15.