Thousands of unvaccinated New York City teachers were placed on unpaid leave after a citywide mandate went into effect, according to the United Federation of Teachers. About 97 percent of teachers and other school staff represented by the union got the vaccine, the United Federation of Teachers President Michael Mulgrew confirmed in a news conference on Monday afternoon. “Under 4,000” of about 121,000 workers represented by the United Federation of Teachers were missing from city schools as of Monday, Mulgrew said in response to a question about how many teachers were taken off the payroll due to the city’s vaccine mandate. He said that individuals who receive the vaccine in the near future can return to work immediately. Some of those unvaccinated teachers have lost “their livelihood,” Mulgrew said, although he stressed that staff should get vaccinated. Mulgrew also stated he is concerned about a lack of school safety officers and …