Robert F. Kennedy Jr. has repeated that not enough childhood vaccines have been tested in clinical trials against a placebo.

The advisory committee makes recommendations to the Centers for Disease Control and Prevention on the nation's vaccine schedule. Any changes could affect vaccinations for millions of children.

As the newly appointed federal vaccine advisory panel prepares to reevaluate childhood vaccination schedules, Gov. Josh Shapiro warns of public health and economic consequences of removing vaccines from recommended schedules.