Data-Driven Assessment of Nonmedical Vaccination Exemption Can Guide Public Health Response.

Abstract

Kindergarten immunization requirements are an important inflection point to ensure children are fully vaccinated before they begin school, but some parents choose to obtain an exemption from school immunization requirements. All states have medical exemptions, and 47 states also offer nonmedical (philosophical and/or religious) ones, with considerable variation in the process to obtain the exemption.1 Eleven states mandate some type of education, ranging from online modules to in-person meetings, before receiving a nonmedical exemption (NME).2Nationally, the proportion of kindergartners with an NME has increased from 1.4% for the 2011–2012 school year to 2.6% for the 2019–2020 school year, whereas medical exemptions have remained at 0.2%.3 Clusters of high exemption rates can lead to outbreaks of vaccine-preventable diseases.4In this issue of Pediatrics, Masters et al5 assess the impact of a 2014 change in Michigan’s administrative rules6 to require parents to attend a vaccine education session at a local health department to obtain an NME. Masters et al5 analyzed school-level data on kindergarten vaccination requirements for 4 years before and after implementation of the new rules (2011–2014, 2015–2018) to calculate medical, philosophical, and religious exemption rates. They mapped school-level exemption rates to the district level and used the local indicators of spatial association to identify school districts with clusters of high exemption rates.Before the administrative rules change, Michigan parents could obtain an exemption at their child’s school, a situation ripe for “convenience exemptions,” in which it was easier for parents to get an exemption than to get their child up to date with vaccination requirements.2 Masters et al5 noted that from 2014 to 2015, immediately after the change in the administrative rules, NME rates fell by 32% but then increased in the 3 subsequent years. In the context of increasing NME rates nationwide,3 these findings suggest that the new NME policy successfully minimized exemptions of convenience but, given reports that few parents changed their decision secondary to the education session at the local health department,7 had minimal impact on exemptions of conviction linked to parental vaccine hesitancy.Overall NME trends mask a marked difference by school type. From 2015 to 2018, public school NME rates increased 25%; although private schools began with a higher NME rate, they had an even slower rate of increase. Over the same period, charter and virtual school NME rates increased ≥80%, suggesting a vastly different trajectory for vaccine hesitance in these settings. The study also identified school-level demographic characteristics (white, college educated, affluent) associated with high NME rates in other studies.8A strength of this study is the differentiation between the 3 types of exemptions and the description of the persistence of clustering over multiple years. The multiyear district-level information provided in this study would be useful to public health officials in every state. It would enable them to better understand the nuances of NME patterns so that they could develop partnerships and devise an array of strategies to address exemptions of conviction, specifically around clusters of religious or philosophical exemptions. This type of data also signals early trends, allowing public health officials to proactively address emerging problems, such as the extremely high NME rate in virtual schools, which are gaining in student enrollment.Although focused on NMEs, the study also revealed areas where persistent medical exemption clusters disappeared after the administrative rules change, as well as the appearance of a new medical exemption cluster. These unexpected patterns serve as a reminder that child health providers should be prudent in offering medical exemptions to vaccination.