Evaluating coverage of malaria vaccination with RTS’s among children aged 6-24 months in selected sub-counties in the malaria-endemic western Kenya Region, 2019 – 2022

Abstract

Objective: To assess malaria vaccination coverage, dropout rates, and proportion of unimmunized children aged 6-24 months in the  malaria lake endemic zone, Kenya.

Design: A retrospective cross-sectional study using routinely reported national program data from health facilities (2019 – 2022).

Setting:  The study was conducted in 26 selected sub-counties of the Malaria Lake endemic zone, Kenya.

Participants: Children 6-24  months of age residing in the malaria lake endemic zone, Kenya.

Intervention: Vaccination using malaria vaccine (RTS, S) dose 1 to 4.  

Main outcome measures: Malaria vaccination coverage, malaria vaccine dropout rate, and proportion of unimmunized children.  

Results: There was a gradual increment in the uptake of malaria vaccine (RTS, S) doses 1 to 4 during the study period. The uptake of  malaria vaccine (RTS, S) 4 was 50% of the desired 80% coverage. The dropout rate progressively declined between malaria vaccination  (RTS, S) 1 to 3 within the threshold of 10%. Dose 4 showed the highest dropout rate (57%). There was a decline in the proportion of  unimmunized children below 1 year over the study period.

Conclusion: Malaria vaccine coverage was satisfactory in doses (1, 2, 3), while uptake of dose 4 was low by two years at (37%). This calls for strategies aimed at enhancing malaria vaccination integration in the second  year of life. Additionally, there is a need to unravel factors associated with high dropout rates and devise measures for minimizing or  eliminating dropout. Enhancing community engagement and advocacy is potentially key for better coverage and maximum protection.