Introduction and roll-out of malaria vaccine in Sierra Leone: early lessons and experiences from the first 8 months of implementation

<h2>Summary</h2> Sierra Leone became the third country globally to roll-out the malaria vaccine, following Cameroon and Burkina Faso. As part of its comprehensive prevention and control measures against malaria, the Government of Sierra Leone, with the support of Gavi, the Vaccine Alliance, UNICEF, and WHO, decided to include the malaria vaccine RTS,S/AS01 into its routine immunisation schedule, after WHO prequalified the vaccine. On Dec 19, 2024, the Sierra Leone Ministry of Health received the first shipment of 550 000 of the 1·7 million doses allocated for 2024–25. Before the roll-out of the vaccines, the Expanded Program on Immunization (EPI) had set a target coverage of 80% for the first dose in the first year of introduction of the malaria vaccine and 50% for the second dose. Nationwide, during the introduction and roll-out of the malaria vaccine, 114 401 (71%) of 161 128 eligible children received the first dose from April to December, 2024; 85 180 (74%) of 114 401 received the second dose from May to December, 2024; and 64 451 (76%) of 85 180 children received the third dose from June to December, 2024. With more than 3 months of data on malaria vaccine introduction readiness in Sierra Leone, the national EPI in Sierra Leone was able to achieve a national preparedness level of 90%, 3 days before the introduction. The malaria vaccine data indicate a positive trajectory towards achieving the EPI's target coverage for the first dose of malaria vaccine, although with some uptake challenges across the second and third doses. These findings highlight the need for effective risk communication among caregivers and robust readiness for vaccine roll-out to enhance vaccine acceptance within communities.