CHICAGO (AP) — Chicago Mayor Lori Lightfoot is touting a preliminary agreement with the teachers union over COVID-19 safety protocols. It could avert a strike in the nation’s third-largest school district. Lightfoot announced the latest proposal Sunday. It includes more vaccinations for teachers. It also pushes back the start of in-person classes and phases them in. The first wave could start this week. Both sides have been negotiating for months over a plan to gradually bring back students in the roughly 340,000-student district. The schools went remote nearly a year ago. The Chicago Teachers Unions isn’t calling it an agreement yet, saying it has to be approved by members.