Estimating the impact of the RTS,S/AS01 malaria vaccine in Benin: A mathematical modelling study

Abstract

AbstractBackgroundMalaria constitutes a major public health burden in sub-Saharan Africa. It remains the primary health concern in health care institutions and the leading cause of death in children under five years of age. Since October 2021, the World Health Organization (WHO) has recommended the RTS,S/AS01 malaria vaccine in children in sub-Saharan Africa and other high burden areas wherePlasmodium falciparumtransmission is moderate to high. However, with the exception of Ghana, there is a scarcity of studies modelling the potential impact of the RTS,S/AS01 vaccine in the context of West Africa. This study addresses a gap in research by modelling the additional impact of malaria childhood vaccination onPlasmodium falciparummalaria transmission in Benin.MethodsA compartmental mathematical model has been developed to estimate clinical and severe malaria cases averted in children under the age of five with the primary series (3 doses) of the RTS,S/AS01 malaria vaccine in Benin. Key features of the model include seasonality and the use of insecticide-treated bed nets. Over a period of 10 years, a number of scenarios of vaccine, coverage are simulated. These scenarios included vaccination introduction at different coverage levels to supplement the use of Insecticide-treated bed nets to assess the impact of the RTS,S/AS01 vaccine on malaria transmission in Benin.ResultsThe model projected outcomes in terms of malaria burden alleviation by childhood vaccination in Benin. The combination of malaria childhood vaccination at a coverage equivalent to the national DTP3 and the current uptake of insecticide-treated bed nets is projected to lead to a 45% reduction in malaria cases and deaths among children under five years old in the country from 2025 to 2034. However, a decrease in the use of ITN is projected to lead to an increase in malaria burden, surpassing baseline levels despite vaccine introduction.ConclusionChild vaccination is expected to avert clinical and severe cases of malaria and is an additional tool to advance malaria control efforts in Benin.