Understanding Kenyan policymakers' perspectives about the introduction of new maternal vaccines.

New vaccine policy adoption is a complex process, especially in low-and-middle-income countries (LMICs), requiring country policymakers to navigate challenges such as competing priorities, human and financial resource constraints, and limited logistical capacity. Since the Expanded Programme on Immunization's (EPI) beginning, most new vaccine introductions under this structure have not been aimed at adult populations. The majority of adult vaccines offered under the EPI are not typically tested among and tailored for pregnant persons, except those that are specifically recommended for pregnancy. Given that new maternal vaccines, including RSV and GBS vaccines, are on the horizon, it is important to understand what barriers may arise during the policy development and vaccine introduction process. In this study, we sought to understand information needs among maternal immunization policymakers and decision-makers in Kenya for new vaccine maternal policy adoption through in-depth interviews with 20 participants in Nakuru and Mombasa counties in Kenya. Results were mapped to an adapted version of an established framework by Levine et al., (2010) focused on new vaccine introduction in LMICs. Participants reported that the policy process for new maternal vaccine introduction requires substantial evidence as well as coordination among diverse stakeholders. Importantly, our findings suggest that the process for new maternal vaccines does not end with the adoption of a new policy, as intended recipients and various actors can determine the success of a vaccine program. Previous shortcomings, in Kenya, and globally during HPV vaccine introduction show the need to allocate adequate resources in education of communities given the sensitive target group. With maternal vaccines targeting a sensitive group - pregnant persons- in the pipeline, we are at an opportune time to understand how to ensure successful vaccine introduction with optimal acceptance and uptake, while also addressing vaccine hesitancy to increase population benefit.