Immunization timeliness and its determinants among young children in Baghdad, Iraq: A cross-sectional study using documented vaccination cards

Background Childhood immunization is a critical public health intervention, yet timeliness remains a challenge in post conflict affected settings like Iraq. This study assessed timeliness of immunization, missed doses, and associated factors with delay among children aged 18–24 months in Baghdad, Iraq. Methods A cross-sectional study was conducted in 11 primary healthcare centers in Baghdad between May and July 2025. Data were collected from 168 children using documented immunization cards. Immunization delay was defined as vaccination administered beyond >28 days of the scheduled date. Multivariate logistic regression was used to identify associated factors. Results Overall vaccine coverage (timely + delayed) remained high (>96%) for first nine months, at 12 and 18 months, coverage declined to 85.1% and 63.7%, respectively. Only 14 children (8.3%) received all vaccinations on time. Immunization delay was observed in 154 (91.7%) children, with 28 (16.7%) of children with delay at a single visit and 126 (75.0%) at multiple visits. Missed doses were highest at 18 months (36.3%), followed by 12 months (14.9%). Timely vaccination dropped sharply from 98.6% at birth to 52.4% at 9 months, and 37.5% at 18months. The most common reason for delay was lack of knowledge about the vaccination schedule (54.8%). In adjusted analysis, lack of knowledge of schedule (aOR = 3.85; 95% CI: 1.04–14.24) and perceived vaccine availability (aOR = 4.74; 95% CI: 1.09–20.51) were significantly associated with delay. No sociodemographic factors were significant. Conclusion Immunization delay is highly prevalent among children in Baghdad. Interventions focusing on caregiver knowledge and ensuring consistent vaccine supply are urgently needed, particularly for children in the second year of life. However, due to purposive sampling, these findings may not be generalizable to all of Baghdad or Iraq.