Factors Associated with Measles Vaccine Immunogenicity in Children at University Teaching Hospitals, Lusaka, Zambia

Measles poses a significant global public health challenge, particularly in low-resource settings where vaccination coverage is limited. This study examined factors associated with measles vaccine immunogenicity in children aged 2 to 15 years at the University Teaching Children’s Hospital and the HIV Pediatric Centre of Excellence in Lusaka, Zambia. This was a comparative analytical cross-sectional study conducted from April to July 2024. Blood samples were collected using a questionnaire uploaded in Kobo. Data analysis was conducted in R-studio. Descriptive statistics were used to summarize respondent data. Bivariate analysis was conducted to test the association between the predictor and outcome variables, while multivariate logistic regression analysis measured the strength of association using adjusted odds ratios (AORs). A p-value < 0.05 was considered significant. Children aged 10 to 15 years were less likely to have retained immunity compared to those aged 2 to 4 years (AOR = 0.270, 95% CI [0.114–0.618], p = <0.002). HIV-positive children had lower odds of retaining immunity compared to HIV-negative children (AOR = 0.290, 95% CI [0.137–0.594], p = <0.001). Children who were breastfed had lower odds of waning immunity (AOR = 0.336; 95% CI [0.147–0.738], p = 0.007) compared to children who were not breastfed. Children residing in Lusaka were less likely to have retained immunity compared to those residing outside Lusaka (AOR = 0.250, 95% CI [0.066–0.859], p = 0.031). These findings show that age, breastfeeding, and HIV status significantly affect the retention of measles immunity in children aged 10-15 years. Younger, HIV-negative, and breastfed children show better immunity retention. These results highlight the protective role of breastfeeding and the need for booster doses to enhance immunity retention, especially for older and HIV-infected children.