The study is suspended pending a protocol amendment.

This study will test whether proactively connecting expectant parents with factual vaccination information during pregnancy can build confidence in vaccinations and lead to timely vaccinations during pregnancy and once their child is born.

In the United States (US), parents' decision to delay or refuse vaccines for their children has resulted in pockets of under-vaccination as well as recurring outbreaks of vaccine-preventable diseases. To increase childhood vaccinations and stem recurring outbreaks, there is a need for effective interventions that build parents' confidence in vaccines and reduce their vaccine hesitancy. The first recommended routine vaccination for children is due at birth. Yet, many parents lack timely or evidence-based information on childhood vaccinations prior to their child's birth. Hence, the researchers of this study propose to evaluate ADEPT - an adaptive intervention that is implemented in prenatal care settings to proactively connect expectant parents with evidence-based information on vaccines recommended during pregnancy and for children after birth. The core component of ADEPT includes prenatal provider trainings and a recommendation to pregnant individuals encouraging vaccinations during pregnancy and for children after birth. Those pregnant individuals who remain vaccine-hesitant despite the provider recommendation will receive adaptive intervention components, which include evidence-based educational materials on vaccinations and phone consultations with a vaccine navigator to discuss any residual concerns.

In the proposed study, ADEPT will be implemented and evaluated in diverse prenatal care practices in North Carolina. Study prenatal care practices will be randomized to the ADEPT intervention or standard of care to pregnant individuals. Individuals receiving prenatal care at a clinic implementing ADEPT will be screened for vaccination intention following the provider recommendation. Vaccine-hesitant pregnant individuals will be offered enrollment into a nested sub-study designed to assess the implementation of the ADEPT intervention. After the pregnant individuals in the intervention and control arms give birth, the researchers will assess their children's vaccination outcomes at birth, 2, 4, 6, and 12 months using data from the North Carolina Immunization Registry (NCIR). The primary study outcome is the difference in timely childhood vaccination at 2 months between the intervention and control arms. In addition, maternal vaccination data will be collected from NCIR for vaccines during pregnancy.

Inclusion Criteria:

• Nulliparous individuals (no prior live birth)
• Singleton pregnancy (excludes twins, triplets, etc.)
• No known fetal congenital malformations or genetic abnormalities
• Not at known risk for preterm birth
• In late second trimester during study recruitment period
• Receive prenatal care at one of the study practices

Inclusion Criteria for Nested Sub-Study:

• Eligible to receive adaptive components of ADEPT (vaccine-hesitant after provider recommendation)
• At least 18 years of age
• Provide informed consent
• Agree to participate in surveys and in-depth interview
• Agree for child's vaccination outcomes to be extracted from the North Carolina Immunization Registry (NCIR)
• Plan to stay in North Carolina for at least 3 months after delivery

Exclusion Criteria:

• none

Datasets related to the primary outcome will be made available after deidentification.

Dataset will be posted after publication of manuscript describing the primary outcome, with no end date.

Individual participant data will be available for sharing with researchers who provide a methodologically sound proposal, in order to achieve the aims in the approved proposal. Proposals should be directed to lavanya.vasudevan@emory.edu. To gain access, data requesters will need to sign a data access agreement.