US kindergarten MMR coverage slips as vaccine exemptions reach 4.2%

Measles, mumps and rubella vaccination coverage among United States kindergarten pupils fell slightly to 92.4% in the latest school-year data, while non-medical vaccine exemptions rose to a record 4.2% nationwide.

The figures, reported from new Centers for Disease Control and Prevention data, show MMR coverage declining by 0.1 percentage point from the previous school year. The share of kindergarten pupils with non-medical exemptions increased from 3.6% to 4.2%, a rise of roughly 17%.

Medical specialists cited in the source report said at least 280,000 kindergarten pupils had not received the MMR vaccine. They warned that national averages can obscure local pockets with much lower coverage, where outbreaks can spread more readily.

The overwhelming majority of US children remain vaccinated, but the new figures arrive during the country’s worst year for measles since 1991, according to the source account. Measles is highly contagious, and public-health agencies generally rely on high, broadly distributed vaccination coverage to limit transmission.

Vaccination requirements for school attendance are set mainly by US states, meaning coverage and exemption rules vary across the country. The data describe a national trend and do not by themselves establish why individual families sought exemptions.