The recent announcement that actress Jenny McCarthy is replacing Elisabeth Hasselbeck on the popular ABC morning talk show The View has sparked an intense wave of backlash.

The problem is that after McCarthy’s son was diagnosed with autism, she became convinced it was because of the measles, mumps, and rubella (MMR) vaccine, and over the last several years she has reinvented herself as the leading celebrity voice of the anti-vaccine movement. Although the study that originally sparked the MMR vaccine-childhood autism panic has since been completely discredited, many parents have stopped vaccinating their children, in part because of anti-vaccine advocacy carried out by McCarthy and others. As a result, measles cases have spiked in recent years.