Open Access Research article

Support for immunization registries among parents of vaccinated and unvaccinated school-aged children: a case control study

Robert W Linkins1, Daniel A Salmon23*, Saad B Omer3, William KY Pan3, Shannon Stokley4 and Neal A Halsey3

Author Affiliations

1 Thailand Ministry of Public Health - US CDC Collaboration, National Center For HIV, STD, and TB Prevention (previously at National Immunization Program), Centers for Disease Control and Prevention, Atlanta Georgia 30333, USA

2 Department of Epidemiology and Health Policy Research, College of Medicine, University of Florida, 1329 SW 16th Street, Room 5239, Gainesville, Florida 32608, USA

3 Department of International Health, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, Room W5041, Baltimore, Maryland 21205, USA

4 National Immunization Program, Centers for Disease Control and Prevention, Mailstop E-05, 1600 Clifton Rd., NE, Atlanta, Georgia 30333, USA

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BMC Public Health 2006, 6:236  doi:10.1186/1471-2458-6-236

Published: 22 September 2006



Immunizations have reduced childhood vaccine preventable disease incidence by 98–100%. Continued vaccine preventable disease control depends on high immunization coverage. Immunization registries help ensure high coverage by recording childhood immunizations administered, generating reminders when immunizations are due, calculating immunization coverage and identifying pockets needing immunization services, and improving vaccine safety by reducing over-immunization and providing data for post-licensure vaccine safety studies. Despite substantial resources directed towards registry development in the U.S., only 48% of children were enrolled in a registry in 2004. Parental attitudes likely impact child participation. Consequently, the purpose of this study was to assess the attitudes of parents of vaccinated and unvaccinated school-aged children regarding: support for immunization registries; laws authorizing registries and mandating provider reporting; opt-in versus opt-out registry participation; and financial worth and responsibility of registry development and implementation.


A case control study of parents of 815 children exempt from school vaccination requirements and 1630 fully vaccinated children was conducted. Children were recruited from 112 elementary schools in Colorado, Massachusetts, Missouri, and Washington. Surveys administered to the parents, asked about views on registries and perceived utility and safety of vaccines. Parental views were summarized and logistic regression models compared differences between parents of exempt and vaccinated children.


Surveys were completed by 56.1% of respondents. Fewer than 10% of parents were aware of immunization registries in their communities. Among parents aware of registries, exempt children were more likely to be enrolled (65.0%) than vaccinated children (26.5%) (p value = 0.01). A substantial proportion of parents of exempt children support immunization registries, particularly if registries offer choice for participation. Few parents of vaccinated (6.8%) and exempt children (6.7%) were aware of laws authorizing immunization registries. Support for laws authorizing registries and requiring health care providers to report to registries was more common among parents of vaccinated than exempt children. Most parents believed that the government, vaccine companies or insurance companies should pay for registries.


Parental support for registries was relatively high. Parental support for immunization registries may increase with greater parental awareness of the risks of vaccine preventable diseases and utility of vaccination.