Strengthening Immunization Quality Using Old Survey Data: Analytical Evidence from the 2014 Cameroon Multiple Indicator Cluster Survey (MICS)

Abstract

Objective: Vaccination coverage in Cameroon remains below targets due to missed opportunities for vaccination (MOV) and delays in timely immunization. This study used data from the 2014 Multiple Indicator Cluster Survey (MICS) to assess vaccination timeliness and MOV, with the goal of proposing a reusable analytic framework for future surveys. Methods: Children aged 12 - 35 months with documented vaccination dates were included. Vaccine doses were classified as early, timely, or delayed based on the national immunization schedule. Timeliness-to-completeness with their 95% confidence intervals (IC) measured how many children were protected on time. Missed opportunity for simultaneous vaccines (MOSV) was defined as the failure to receive one or more vaccine due doses during a health system contact. Uncorrected missed opportunity for vaccination (uncorrected MOV) was defined as a child who missed one or more due vaccine doses during a contact and did not subsequently return to receive the missed vaccine(s). All uncorrected MOVs refer to children who failed to receive all due vaccines that were missed during eligible contacts. Analyses included descriptive statistics, meta-analysis of MOV proportions, stratified comparisons, and modeling based on the “All uncorrected MOSV” status with a stepwise logistic regression analyses completed with a decision tree classification. Results: Of 1447 children (65.3% of cards ownership), 66.1% (95% CI = 63.6 - 68.5) were fully vaccinated among which only 11.3% (95% CI = 9.4 - 13.5) received vaccines on time. Timeliness was below 80% for all antigens, from 34.7% (BCG) to 61% (Penta1). Timely and completeness for specific doses ranged from 27% to 52%. MOV for simultaneous vaccines (MOSV) prevalence was 90% (95% CI = 84 - 94) nationally, among which 61% (95% CI = 53 - 69) of children had ALL uncorrected MOSV. MOV was significantly more frequent in rural areas and varied by maternal education, wealth, region, and care use. Dose specific MOV ranged from the lowest of 4% (56/1413) for BCG, to the highest of 53.04% for the yellow fever, to 57.1% for PCV vaccines. A significant difference in MOV between sexes indicates gender-related inequities. Conclusion: Although based on an older survey, this study demonstrates a methodology for analyzing vaccination data, encompassing both timeliness and combined timeliness-completeness, as well as missed opportunities for vaccination (MOV). The MOV analysis highlights equity gaps and underscores the importance of community-driven, gender-sensitive strategies to strengthen vaccine delivery. Additionally, the observed association between maternal experience of domestic violence and the occurrence of missed opportunities for simultaneous vaccination warrants further investigation.