Innovative approach in assessing the children's immunization status when it cannot be documented.

During surveys, it is recommended that children immunization status should be based on immunization documents. It has been noted that in some communities, a number of children are claimed to be vaccinated but have no evidence of vaccination. This work is proposed to estimate routine immunization coverage in children based on both documented vaccination and the tracking of undocumented immunization. It was a community-based survey targeting children aged 0-59 months in which the immunization status of children was assessed based on vaccination documents and based on a questionnaire tracking immunization sites and period for children with undocumented vaccination. The vaccination coverage and completeness were estimated from data collected in immunization cards and re-estimated after tracking the immunization status of children with no immunization cards. Of 1435 children reached in households, 1430 (99.7%) were included. Of 1072 children aged 12-59 months, 194 (18.1%) received DPT-Hi+Hb 3 with evidence and 399 (37.2%) with evidence and tracking. In the same age group, the dropout rate from DPT-Hi+Hb 1 (157 doses administered) to DPT-Hi+Hb 3 (127 doses administered) with evidence was 19.1% and 42.4% with evidence and tracking. The tracking of immunization status in children with no evidence of vaccination allows to determine their immunization status and to improve the reliability of the estimated vaccination coverage. This strategy could be adopted to be part of the planning and implementation of vaccination coverage surveys of EPI vaccines.