Note appeared on private Facebook group called UTLA FB Group - Members Only, which has 5,700 members Screenshot of the warning was leaked three days after most United Teachers Los Angeles members voted against resuming in-person instruction Union is demanding that LA County be removed from so-called 'purple tier,' which is the state's most restrictive set of COVID rules Returning staff must be fully vaccinated or have access to vaccine doses and coronavirus safety measures must be in place in the classrooms UTLA stated it is not responsible for and does not monitor content in Facebook group