Over half of Arizona’s kindergarten classrooms did not have MMR immunization rates needed for herd immunity in 2018, according to the Arizona Department of Health Services.
And in Maricopa County, the percentage is even higher, according to state statistics. In the state’s most populous county, just under 62% of schools with kindergarten classes are not at coverage levels needed to stop a measles outbreak.
Data also showed that MMR immunizations rates continued a downward trend in 2018, dropping to 92.7% from 93.1% in 2017 and 93.8% in 2016 in Maricopa County. Other vaccines, including polio and DTaP, show similar decreases.
Students using personal belief exemptions to opt out of all vaccines continues to rise, according to ADHS. Over the last four years, the personal exemption rate has doubled, from 1.9% in 2015 to 4.0% in 2018.
The state pointed out that personal belief exemption rates for all vaccines are much higher at private and charter schools -- both 9.8% -- than at public schools -- 5.3%.
Over the same period, rates of medical exemptions have remained steady in Maricopa County, with 0.3% of students having a medical exemption in 2015 and 2018.
DHS says based on the latest data, over 5,000 Arizona kindergartners are at risk of contracting measles in an outbreak.
According to the CDC, community or herd immunity is when "a sufficient proportion of the population is immune to an infectious disease to make its spread from person to person unlikely."
Community immunity is especially important for protecting those who can't be vaccinated, such as newborns and people with chronic illnesses or compromised immune systems, the CDC says.
ADHS says 95% vaccination rates are needed for community immunity.
The state reported the statistics in its annual Immunization Data Report. The report compiles data submitted by each school to Arizona DHS annually by November 15. The survey specifically focuses on immunization rates in child care/preschool, kindergarten, and 6th grade.
To learn more about kindergarten immunization rates at schools across the state, explore 12 News’ interactive map.
This map shows the kindergartens -- more than 1,000 of them -- across Arizona that have more than 20 students enrolled.
The orange markers represent schools that do not meet the 95% threshold for MMR immunizations. The blue dots represent schools that do have more than 95% immunizations.
Users can search a school name to have their schools show up and hovering over or clicking a location will give detailed info about the MMR vaccines.