Seventy-six percent of American adults now say the measles, mumps, and rubella vaccine is safe for children, down from 84 percent six years earlier, according to a four-day Reuters/Ipsos poll completed this week. The decline was most pronounced among Republicans, and it lands in the worst measles year the country has recorded in more than three decades.
The number matters because confidence tends to move before coverage does. National kindergarten MMR coverage has fallen below the roughly 95 percent needed for community immunity, the threshold that protects infants too young for a first dose and children who cannot be vaccinated.
