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 evaluated in a cluster-randomized pilot implementation programme in three African countries. This study seeks 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, 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% was calculated. Multilevel logistic regression was used to explore patterns of overlap by demographic and socioeconomic variables. 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, was also estimated. 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. It was 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 up to an estimated 9.7 million (range 8.5–10.8 million) clinical malaria cases each year, assuming all children who receive DTP3 are administered all four RTS,S doses. An additional 10.8 million (9.5–12.0 million) cases could be averted by vaccinating those 24 million children who receive the DTP3 vaccine and use an ITN. Children who had access to or used an ITN were 9–13% 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.

Unravelling factors associated with malaria parasitaemia among children 6–24 months to inform malaria interventions in Nigeria: evidence from 2021 Malaria Indicator Survey

“…Another study also showed that malaria is well acknowledged as a disease of poor communities common in rural areas [ 17 , 37 ]. As progress made in reducing malaria prevalence in children is a measure to assess the achievement of leave no one behind global ambition [ 14 ], additional interventions such as malaria vaccine which has a high potential of reducing inequality of accessing existing intervention should target underserved children to protect them from malaria [ 38 ].…”

Malaria vaccination: hurdles to reach high-risk children

“…Why will the outcome be different when it comes to the malaria vaccine? The potential of malaria immunization to reduce inequity in access to existing interventions [ 26 ] can only be realized if the hurdles indicated here are addressed effectively. Otherwise, malaria vaccines may increase inequity.…”

Assessing Geographic Overlap between Zero-Dose Diphtheria–Tetanus–Pertussis Vaccination Prevalence and Other Health Indicators

“…Spatial analyses conducted in recent years have emphasized the substantial degree of subnational inequality in vaccine coverage [13,[17][18][19][20][21][22][23], as well as other key health services and indicators [22,[24][25][26][27][28][29][30][31]. Fewer studies have assessed whether subnational distributions of zero-dose (or no-DTP) children are similar to those for other health indicators [32]. Some publicly available tools, such as the WHO Health Equity Assessment Toolkit [33], allow for powerful comparisons of health indicators within countries, although only for the years in which surveys have been conducted, and are limited to the geographic resolution of traditional survey methods (e.g., the first administrative level).…”