Measles outbreaks alarm U.S. health officials

Health professionals are sounding the alarm as seven out of 14 counties in Massachusetts no longer meet the threshold for herd immunity.

The decline in immunization is being attributed to a rise in religious vaccine exemptions and the influence of anti-vaccine activists in statehouses.

Babies too young for the MMR shot are being described as 'sitting ducks' in communities where the virus is spreading rapidly.

Health officials are urging parents to prioritize vaccinations to prevent the return of a disease that was once considered eradicated in the United States.