As U.S. Measles Outbreaks Spread, Why Does 'Anti-Vax' Movement Persist?

As U.S. Measles Outbreaks Spread, Why Does 'Anti-Vax' Movement Persist?: Measles outbreaks across the United States -- including one in Washington state where 50 cases have now been identified -- have again shone the spotlight on parents who resist getting kids vaccinated.