Updated Feb. 10, 11:45 a.m.: This story and database have been changed to reflect the addition of immunization data for Adams County School District 50.

It’s well known that Colorado has lower immunization rates and higher exemption rates than most other states, but those numbers are based on small survey samples and don’t reveal much about the risk in individual schools and communities. That’s why school-by-school rates can provide a valuable yardstick for parents, particularly in households with immunosuppressed family members or infants and young children who haven’t yet been fully vaccinated.

Now you can use Chalkbeat’s database—the first of its kind in Colorado–to look up immunization compliance and exemption rates for individual schools in the 20 largest districts in the state. These districts enroll around three-quarters of the state’s students.

Under House Bill 14-1288, which took effect last July 1, schools are required to disclose immunization and exemption rates upon request. No state agency currently collects or compiles this data.

Here’s some information about terminology in the database:

Compliance rates include the percentage of students who have gotten all required immunizations, have signed exemption forms, or are “in process” of getting up to date on their immunizations. High compliance rates indicate that schools are doing a good job collecting immunization and exemption paperwork, and ensuring that students are complying with state law. High compliance rates do not necessarily indicate that all those student are fully immunized.

Exemption rates represent the percentage of students whose parents have opted them out of some or all required shots. In Colorado, there are three types of exemptions: medical, religious, and personal belief. The majority of parents who excuse their children from immunizations use personal belief exemptions.

High exemption rates—around 10 percent or higher–can have serious implications when there are outbreaks of contagious diseases like measles and whooping cough. That’s because herd immunity usually requires immunization rates of 90-95 percent. If too many students in a school have opted out of shots, the spread of disease is more likely. The same may be true when compliance rates drop below 90 percent, even if exemption rates are low.

To find immunization and exemption rates for schools not listed in this database, make a direct request to the school or district of interest. Then let us know that information and we’ll add it to our database.

Note: Most districts provided compliance and exemption rates for their charter schools, but a few, including Poudre School District, did not. If you would like to add your school’s or district’s rates, please send an email to co.tips@chalkbeat.org.