Influencing factors on missed opportunities for vaccination among children aged 0-24 months in hospitals of White Nile State, Sudan: a mixed method study.

Introduction: Missed Opportunities for Vaccination (MOV) is one of the reasons contributing to low and inequitable vaccination coverage. We conducted a mixed method study to assess prevalence of MOVs among children aged 0-24 months in hospitals of White Nile State, Sudan during 2023 as well as to identify underlying causes of MOVs. Methods: for quantitative assessment, caregivers of 226 children with vaccination cards and ages 0-24 months (mean 8.3 months; standard deviation 5.7; 45% male) were interviewed when they visited 18 hospitals. Stata v18 and the programme Missed Opportunities Vaccination Coverage Quality Indicators (MISS VCQI) were used to analyse the children's vaccination history data. Multivariable logistic regression was used to assess association between the main outcome variable (occurrence of MOVs) and independent variables. For a qualitative perspective, hospital documents and Ministry of Health policies were reviewed for MOV-related content. Ideas about underlying causes of MOVs were elicited in focus group discussions with health workers and caregivers and in in-depth interviews with hospital managers and senior staff. Results: on the study day, 187 children were eligible for one or more doses. Fifty-seven (30.5%) received all the doses they were due and 130 (69.5%) experienced MOVs. Of the 678 doses that were due, 445 (65.6%) were received and 233 (34.3%) were not. MOVs were most prevalent for the dose BCG (63.2%) and least prevalent for OPV (6.5%). Broadening the analysis to all 226 children with cards and to all their documented vaccination visits both on and before the study day, 152 (67.3%) had experienced an MOV on at least one vaccination visit. MOVs were less likely to occur in a) children who were born at a health facility (aOR 0.52, 95% CI 0.29-0.95; P=.03), b) children whose caregiver has secondary or higher education (aOR 0.35, 95% CI 0.18-0.67; P=0.002), and c) in families where the father alone makes decisions about childhood vaccination (aOR 0.31, 95% CI 0.14-0.69; P=0.004). Stakeholders identified likely reasons for MOVs, including stock deficiencies of vaccines and syringes, inconvenient scheduling of vaccination sessions, and health worker aversion to opening a multi-dose vaccine vial for a single child. We found no federal or state level policies in place to address MOVs. Conclusion: quantitatively, a high prevalence of MOVs was observed which contributes to low vaccination coverage in White Nile State. Qualitatively, stakeholders identified factors that might be addressed to minimize the occurrence of MOVs.