Reducing Delay of Vaccination in Children Study (REDIVAC)

This trial will assess the effectiveness of a tailored message intervention on decreasing infant undervaccination.

This intervention is based on the concept of "message tailoring," whereby each mother is provided with individually customized vaccine- related information that addresses their unique concerns, values, questions and logistical barriers. Message tailoring is an evidence-based health messaging strategy that has been shown to improve compliance with a wide variety of preventive health care behaviors among diverse patient populations. In this three-armed trial the investigator will examine how providing mothers with multiple "doses" of a tailored versus untailored version of our intervention compares with "usual care" for the impact on infant under-vaccination. Secondary outcomes will include maternal vaccine-related attitudes (including level of vaccine hesitancy), alignment of maternal values with provider recommendations, and self-efficacy for overcoming logistical barriers to vaccination.

Participants will complete surveys at each intervention time point. Based on survey responses, they will receive vaccine information on the study website tailored to their vaccine concerns and values

Participants will complete surveys at each intervention time point and receive vaccine information on the study website. The vaccine information will NOT be tailored to their concerns and values.

Participants will complete surveys at each intervention time point. They will receive vaccine information sheets that are provided in the well child visits at enrollment in the study.

Pregnant women will be recruited to the study. The intervention will be delivered to participants prior to the child's 2 month well child visit, when the child is between 4 and 6 months of age, and when the child is 10-12 months of age. The first intervention occurs at enrollment in the study. Participants in the tailored intervention arm will receive vaccine information tailored specific to her concerns and values at each intervention point.

Pregnant women will be recruited to the study. The intervention will be delivered to participants prior to the child's 2 month well child visit, when the child is between 4 and 6 months of age, and when the child is 10-12 months of age. The first intervention occurs at enrollment in the study. Participants in the untailored arm will receive vaccine information at each intervention time point, but it will not be tailored to her specific concerns.

assessed using both a continuous and dichotomous measure. Continuous: measure of average days under-vaccinated is a recently developed metric measuring the average number of days a child is unvaccinated based on the vaccines given and the date when the vaccines where given. Dichotomous: mesauring the child's days undervaccinated or whether or not the child is up-to-date with no vaccination delays.

Maternal vaccine attitudes are collected from survey items and include attitudes and beliefs about vaccines as well as level of vaccine hesitancy

Health values related to vaccines are measured from survey items and include conformity, security, power, self-direction, and universalism

Inclusion Criteria: Enrolled at Kaiser Permanente Colorado, Pregnant in the 3rd trimester, and plan to use Kaiser Permanente Colorado for the child's medical care received. Exclusion Criteria: less then 18 years of age, non-english speaking and an inability to consent

Glanz JM, Wagner NM, Narwaney KJ, Pyrzanowski J, Kwan BM, Sevick C, Resnicow K, Dempsey AF. Web-Based Tailored Messaging to Increase Vaccination: A Randomized Clinical Trial. Pediatrics. 2020 Nov;146(5):e20200669. doi: 10.1542/peds.2020-0669. Epub 2020 Oct 12.

Dempsey AF, Wagner N, Narwaney K, Pyrzanowski J, Kwan BM, Kraus C, Gleason K, Resnicow K, Sevick C, Cataldi J, Brewer SE, Glanz JM. 'Reducing Delays In Vaccination' (REDIVAC) trial: a protocol for a randomised controlled trial of a web-based, individually tailored, educational intervention to improve timeliness of infant vaccination. BMJ Open. 2019 May 22;9(5):e027968. doi: 10.1136/bmjopen-2018-027968.