<p>COREQ 32 – Item checklist.</p>

Community birth attendants (CBAs) represent an insufficiently integrated resource in childhood immunization programs, particularly in urban slum communities where healthcare access remains challenging. Their role as birth attendants has been well documented, however, understanding their role in infant vaccination uptake is crucial for improving immunization uptake and child welfare. This study explored the knowledge of CBAs about infant immunization and assessed their roles in promoting vaccination uptake in urban slum communities of Ibadan, Nigeria. A narrative study design was employed across eight urban slum communities in three local government areas of Ibadan. Six focus group discussions were conducted with 37 CBAs using an interview guide developed in Yoruba language. Data were analyzed using content analysis, guided by the knowledge, attitude and practice model. CBAs had a good understanding of immunization as a disease prevention strategy and had comprehensive knowledge of birth dose vaccines’ (BCG, OPV, Hepatitis B) names and timing. However, knowledge about the other immunization visits’ timing varied considerably among them. CBAs generally had positive attitude towards immunization. They played diverse roles in immunization process including community mobilization for immunization campaigns, health education, referral to immunization clinics, appointment reminders, identification and support of zero-dose children, and providing transportation assistance when mothers were unable to attend clinics. Their trusted position within communities and informal collaboration with primary health centers positioned them as vital intermediaries in vaccination uptake. Key barriers included limited vaccine knowledge, lack of formal recognition by healthcare workers, and poor self-efficacy in navigating vaccination procedures. Despite knowledge gaps and systemic barriers, CBAs serve as crucial facilitators of infant immunization in urban slum communities in Ibadan, through their trusted relationships and comprehensive support activities. Formal integration of CBAs into immunization programs, coupled with targeted training and recognition, could significantly enhance vaccination coverage in disadvantaged urban populations.