Intervention
The package of interventions included; house-to-house registration of children under-one-year (in both intervention and control arms); health facility based audit meetings to review immunization data (in intervention arm); and defaulter tracking through home visits (in the intervention arm). The study interventions were implemented from July to September 2020. A total of 15 facility-based health workers and 51 CHWs (also locally known as village health teams who are unpaid volunteers) were oriented in the study protocol and implementation process. From each health facility, 5 health workers and 17 CHWs were chosen. In addition, they were given refresher training on basics of EPI; service delivery; data management (including review of EPI performance); vaccine management; advocacy, communication and mobilization. The training lasted for five days one month before implementation of the study interventions. The CHWs tasks included attending the data audit meetings and conducting home visits to trace and link children defaulting at their immunization schedules. They were supervised by the health workers involved in EPI service delivery at their respective health facilities to which they were attached.The tasks of the health workers included organizing the data audit meetings; identifying children defaulting at their immunization schedules; reconciling the defaulters who had returned for immunization; and supervising the CHWs.At baseline, for both the intervention and control arm, house-to-house registration of eligible children for immunization (0-12months) was performed as well as information on un/under-immunized children (children 0–12 and 13–23 months) who had not received/defaulted on DPT3 and or MR was recorded by CHWs using a designed tool. The CHWs advised and encouraged caregivers of the identified un/under-immunized children to take them for catch-up vaccination at the nearest health facility. Data from this house-to-house registration was used to update the health facility target population. Immunization activities in the control arm at static and outreaches continued as per the health facility schedules.In the intervention arm, monthly immunization data audit meetings with health facility staff and CHWs were conducted to discuss the health facility based EPI performance and generate a list of children defaulting immunization services. These immunization data audit meetings were held on monthly basis for three months at the intervention health facilities. For a given sitting, the audit meetings would last for an average of two hours. The defaulters identified through the audit meetings were then followed up and linked to health facility by CHWs through home visits. Linkage involved advising the caregiver(s) to take their defaulting children to the health facility for catch-up vaccination services. In the subsequent data audit meetings, the CHWs would report on the outcomes of tracing defaulters through home visits. In addition, they would also validate the immunization status of defaulters linked through review of the immunization registry. In the non-intervention arm, immunization activities at the static health facilities and outreaches continued as per their health facilities’ schedules. CHWs were not given any remuneration. They were given airtime for communication and transport funds to facilitate their activities.