A mother in Los Angeles says her son was vaccinated at school without her consent and in exchange for pizza. “I should have been involved,” Maribel Duarte told NBC 4 News, whose 13-year-old son attends the Barack Obama Global Prep Academy in South Los Angeles. Duarte also says her son was told to not discuss what happened. “The lady that gave him the shot and signed the paper told my son, ‘Please don’t say anything. I don’t want to get in trouble.'” “It hurt to know he got a shot without my permission, without me knowing and without signing any papers for him to get the shot,” Duarte said. A school administrator told NBC the allegations aren’t true and that “more often than not, parents will lie about the whole vaccine issue.” Duarte, who is vaccinated, says she didn’t want her son to get the shot because of health issues …