Factors influencing the performance of routine immunization in urban areas: A comparative case study of two cities in Cameroon: Douala and Yaoundé.

Urban areas are often omitted from investigations on immunization because the published literature tends to focus on rural settings. The two largest cities in Cameroon - Douala and Yaoundé - are the main drivers of the high number of unvaccinated children in Cameroon. The objective of our study was to identify the factors influencing vaccine incompleteness in Douala and Yaoundé in children (12-23 months of age). We conducted a community-based cross-sectional study using concomitant mixed methods (qualitative and quantitative) with an explanatory aim. The study was conducted in three health districts in each city between March and April 2016. The number of nonvaccinated and incompletely vaccinated children was higher in Yaoundé (3.1% and 40.3%, respectively) than in Douala (0.7% and 10.1%, respectively). The most frequent reason for nonvaccination was related to the parent/guardian not knowing the consequences of not being vaccinated and lack of money. According to the explanatory model, nonvaccination in both cities was associated with the following issues: (1) perceived high visibility of the health district office in terms of vaccination, (2) the shortage of health personnel in immunization centers, (3) attending a private health facility, (4) average or poor behavior of health personnel at immunization centers, and (5) poor knowledge of vaccine-preventable diseases. This mixed-methods study illustrates how inadequacies of the health district framework within urban areas are fueling poor performance of routine immunization in Cameroon. Further research should inform the development of community-centered vaccination services that are most needed, especially in rapidly urbanizing sub-Saharan Africa.