Analysis of the potential for a malaria vaccine to reduce gaps in malaria intervention coverage

Abstract

Background: The RTS,S/AS01 malaria vaccine is currently being piloted in three African countries. We sought to identify whether vaccination could reach additional children who are at risk from malaria but do not currently have access to, or use, core malaria interventions. Methods: Using data from household surveys we calculated the overlap between malaria intervention coverage and childhood vaccination (diphtheria-tetanus-pertussis dose 3, DTP3) uptake in 20 African countries with at least one first administrative level unit with Plasmodium falciparum parasite prevalence greater than 10%. We used multilevel logistic regression to explore patterns of overlap by demographic and socioeconomic variables. We also estimated the public health impact of delivering RTS,S/AS01 to those children who do not use an insecticide-treated net (ITN) but who received the DTP3 vaccine. Results: Uptake of DTP3 was higher than malaria intervention coverage in most countries. Overall, 34% of children did not use ITNs and received DTP3, while 35% of children used ITNs and received DTP3, although this breakdown varied by country. We estimated that there are 33 million children in these 20 countries who do not use an ITN. Of these, 23 million (70%) received the DTP3 vaccine. Vaccinating those 23 million children who receive DTP3 but do not use an ITN could avert an estimated 9.7 million clinical malaria cases each year. An additional 10.8 million cases could be averted by vaccinating those 24 million children who receive the vaccine and use an ITN. Children who had access to or used an ITN were 9 to 13% more likely to reside in rural areas compared to those who had neither intervention regardless of vaccination status. Mothers' education status was a strong predictor of intervention uptake and was positively associated with use of ITNs and vaccination uptake and negatively associated with having access to an ITN but not using it. Wealth was also a strong predictor of intervention coverage. Conclusions: Childhood vaccination to prevent malaria has the potential to reduce inequity in access to existing malaria interventions and could substantially reduce the childhood malaria burden in sub-Saharan Africa, even in regions with lower existing DTP3 coverage.