Assessing immunization coverage in Southern togo: implications for perennial malaria chemoprevention delivery

Malaria remains a major health challenge in sub-Saharan Africa, especially for children under five. The World Health Organization (WHO) recommends perennial malaria chemoprevention (PMC) to children in areas of medium to high perennial transmission. In Togo, since 2022, a pilot project has leveraged the Expanded Program on Immunization (EPI) to deliver PMC to children under two years; however, the extent to which PMC achieves its desired outcome may depend on EPI performance. This study assessed EPI coverage and factors associated with zero-dose status in southern Togo.

We used secondary data from a multi-stage sampling household survey on malaria prevalence conducted in the Haho district in 2022, focusing on children aged 12-23 months. Vaccination history was obtained via EPI cards or caretaker recall. Immunization coverage was defined according to the WHO criteria. Factors associated with zero-dose, defined as the absence of the first diphtheria-tetanus-pertussis-containing vaccine, were assessed using mixed-effects multivariable logistic regression models. Potential risk factors included caretaker and household characteristics, vaccination perceptions, and geographic access. Sensitivity analyses were performed to validate caretaker-reported data.

Among 583 children, 60.7% were fully immunized, and 15.8% were classified as zero-dose. Key barriers for vaccination included family discouragement (17.4%), lack of time (15.1%), and COVID-19-related issues (14%). Vaccine uptake declined with age, from 84% at birth to 35% for the second measles vaccine at 15 months. Zero-dose status was significantly associated with low caregiver education (adjusted odds ratio [aOR] 5.02, 95% confidence interval [CI] 1.85-13.60), negative attitudes toward vaccination safety (aOR 8.60, 95% CI 3.32-22.30), and lack of reliance on modern healthcare (aOR 3.06, 95% CI 1.26-7.48). Access to the nearest health facility, whether measured by distance (P = 0.86) or time (P = 0.11), showed no significant association.

The suboptimal immunization coverage and a high proportion of zero-dose children highlight the need to strengthen community engagement to improve vaccination awareness and ensure the effective and equitable delivery of PMC.