Measles-Specific IgG Antibody Levels and Associated Demographic and Vaccination Factors Among Children in Diyala Governorate, Iraq: A Cross-Sectional Study

Measles is a significant cause of death in children, despite the availability of safe and cost-effective measles vaccines. Monitoring measles-specific IgG antibody levels is essential for evaluating vaccine-induced immunity and identifying factors associated with protective immune responses. This study was aimed to assess of measles IgG antibody levels and identify associated factors affecting measles immunity among children in Diyala Governorate / Iraq. A cross-sectional study was conducted between October 1, 2025, and April 30, 2026. Ninety children aged 1–14 years who had received at least one dose of a measles-containing vaccine were enrolled from primary health care centres in Diyala Governorate. Venous blood samples were collected, and serum anti-measles IgG antibody concentrations were determined using the enzyme-linked immunosorbent assay (ELISA). Demographic characteristics and vaccination history were obtained through a structured questionnaire. Statistical analysis was performed using SPSS version 29, with statistical significance set at P < 0.05 Among the 90 enrolled children, 53.3% were males and 46.7% were females. Female children showed significantly higher measles IgG antibody concentrations than males (64.74 ± 58.91 vs. 46.60 ± 46.55 ng/L; P = 0.006). No significant differences in measles IgG antibody concentrations were observed according to vaccination status (65.77 ± 73.29 vs. 50.48 ± 41.64 ng/L; P = 0.682) or age groups (P = 0.341). Furthermore, a weak positive correlation was found between measles IgG antibody concentration and the number of vaccine doses; however, this correlation was not statistically significant (r = 0.070, P = 0.512).