Mandatory School Immunization Laws in the United States: Historical origins, policy implementation, and assessing the impact of strengthening exemption requirements

Abstract

Problem Statement: High immunization coverage among school-age children has been achieved in the United States through the collaborative efforts of federal agencies, state administrations, health care providers, and medical societies supporting a common objective.[1]

However, recent parental vaccine hesitancy and refusal trends have been at least partially responsible for regional decreases in immunization coverage rates, increases in state exemption rates, and outbreaks of vaccine preventable diseases. State immunization mandates are an important strategy in protecting children from vaccine-preventable morbidity and mortality. Several states have responded to high exemption rates in their state by passing more restrictive exemption legislation.

Methods: This study assessed immunization and exemption mandates in the US in three ways: (1) a literature review and analysis of the evolution of state immunization mandates from 1902-2017; (2) a qualitative assessment of the implementation of restrictive exemption laws in Washington, California, Oregon, and Vermont between 2011-2016; and (3) an impact assessment of exemption rate changes in Vermont between 1989-2016.

Results: We found that while all US states and Washington DC have school immunization mandates requiring vaccines for childcare and school entry, there is considerable diversity across states in how states historically began mandating vaccines, the requirements for school entry, the populations to which mandates apply, the types and requirements of exemptions available, implementation and enforcement of mandates, and how states respond to new recommendations.

Through 81 in-depth interviews with stakeholders from state and local health departments, school nurses and health personnel, and immunization experts, we explored barriers and facilitators to effective implementation of new laws. We also found that exemption rates in Vermont were responsive to state vaccine law and policy changes. Changes in vaccine requirements in 2008, 2012, and 2015 impacted exemption rates in public and private schools in Vermont, but non-medical exemptions did not decrease until philosophical exemptions were removed in 2016.

Discussion: The results of this study will support legislative and administrative decision-making at state and local health departments, provide evidence to support mandatory immunization law changes at the state level, and support the implementation of requirements at the school level. The variability across state immunization law enactment and implementation has influenced the effectiveness of school mandates and the ease of the exemption requirements. Strengthening exemption requirements to include educational information and increasing the administrative complexity of non-medical exemption requirements is an effective strategy to lower non-medical exemption rates.