Preferences for Immunization Coverage in Health Plans

Download data and study materials from OSF

Principal investigators:

Matthew M. Davis, MD, MAPP

University of Michigan



Kathryn Fant

University of Michigan


Sample size: 1101

Field period: 06/18/2004-07/12/2004


"Underinsurance" for recommended vaccines in private health plans may affect 15 percent of children and more than 30 percent of adults, creating an economic barrier to immunization. We conducted a nationally representative, Web-based study using health plan vignettes to determine adults' willingness to bear marginally higher plan premiums in order to assure plan coverage of new vaccines as they are recommended for children and adults.


a) Individuals and families are willing to bear incrementally higher premiums in their private, employer-sponsored health plans in order to have the guarantee of coverage for newly recommended vaccines.
b) Individuals who are reminded of the "public good" aspect of vaccination will be more likely to bear incrementally higher premiums to assure a coverage guarantee for newly recommended vaccines.

Experimental Manipulations

The sample was stratified with equal representation of households with and without minor children. Each stratum was then randomized to receive information about the potential health and economic benefits of child and adult immunizations, in one of two forms:
a) "personal benefits" - emphasized the potential health benefits and economic savings from insurance coverage for immunizations (rather than facing out-of-pocket costs)
b) "personal benefits + public good" - along with the benefits specified in (a), also emphasized the potential benefits for members of the subjects' communities who might receive new vaccines instead of them, or who might not be able to receive the new vaccine because of health issues but who would benefit from the subjects' receipt of vaccine.


a) Choice of "comprehensive" vaccine coverage in a hypothetical health plan (to include a guarantee of coverage for any child or adult vaccine newly recommended by the Centers for Disease Control and Prevention) versus "basic" coverage (coverage of most currently recommended
b) For those who did not opt for "comprehensive" coverage, their willingness to pay out-of-pocket for a newly recommended vaccine if it were recommended for themselves and/or their child(ren) by a physician

Summary of Results

Underinsurance for recommended vaccines in private health plans may affect 15 percent of children and more than 30 percent of adults. Our results indicate a broad willingness (more than 75 percent of respondents) to pay the higher premiums. Such willingness was associated strongly with perceptions of vaccines' effectiveness and safety.


Policymakers, physicians, and public health officials should examine health plan enrollees' preferences as they consider remedies for vaccine underinsurance.

Additional Information

We also measured respondents' general attitudes about vaccine effectiveness for children and adults, as well as attitudes about general vaccine safety, and investigated whether there were associations between such attitudes and respondents' choices of health plans and willingness to pay for newly recommended vaccines out of pocket.


Davis, M. M., and K. Fant. 2005. "Coverage Of Vaccines In Private Health Plans: What Does The Public Prefer?." Health Affairs 24:770.