“While the recent federal announcement calls for exploring separate measles, mumps and rubella vaccines, single-antigen measles, mumps and rubella vaccines are not available in the United States,” Irwin said. “Families should not wait for a hypothetical future vaccine option when the MMR vaccine is available and has a long history of protecting children.” President Donald Trump signed an order on Monday that called for fewer childhood vaccines and recommended splitting the MMR shots. The Pennsylvania Department of Health requires all students in grades K–12 to receive two doses of the measles, mumps and rubella vaccine for school attendance. As of Thursday, there were more than 2,400 confirmed measles cases reported in the states, according to the Centers for Disease Control and Prevention.