Production assistants on three shows produced by Warner Bros. Television — Abbott Elementary , George & Mandy’s First Marriage and All American — have ratified their first union contracts. The staffers, about 15 in total, unanimously voted to ratify the three separate contracts in a vote that ended Tuesday, The Hollywood Reporter has learned. Their union, Production Assistants United , is affiliated with the Hollywood laborers’ union LiUNA Local 724. “You cannot run a production without production assistants,” Production Assistants United director of organizing Ethan Ravens said in a statement. “The idea that the workers holding productions together should have a union, a voice, health care and a pension is not radical. It is inevitable. These contracts prove the momentum is real, and it is only going to keep growing.” THR has reached out to Warner Bros. Television for comment. The deals qualify production assistants on these shows, which all film at Burbank’s Warner Bros.…