Impact of seasonal RTS,S/AS01E vaccination plus seasonal malaria chemoprevention on the nutritional status of children in Burkina Faso and Mali

Abstract

Background: A recent trial in Burkina Faso and Mali showed that combining seasonal RTS,S/AS01E malaria vaccination with seasonal malaria chemoprevention (SMC) substantially reduced the incidence of uncomplicated and severe malaria in young children compared to either intervention alone. Given the possible negative effect of malaria on nutrition, the study investigated whether these children also experienced lower prevalence of acute and chronic malnutrition.

Methods: In Burkina Faso and Mali 5920 children were randomized to receive either SMC alone, RTS,S/AS01E alone, or SMC combined with RTS,S/AS01E for three malaria transmission seasons (2017-2019). After each transmission season, anthropometric measurements were collected from all study children at a cross-sectional survey and used to derive nutritional status indicators, including the binary variables wasted and stunted (weight-for-height and height-for-age z-scores below - 2, respectively). Binary and continuous outcomes between treatment groups were compared by Poisson and linear regression.

Results: In 2017, compared to SMC alone, the combined intervention reduced the prevalence of wasting by approximately 12% [prevalence ratio (PR) = 0.88 (95% CI 0.75, 1.03)], and approximately 21% in 2018 [PR = 0.79 (95% CI 0.62, 1.01)]. Point estimates were similar for comparisons with RTS,S/AS01E, but there was stronger evidence of a difference. There was at least a 30% reduction in the point estimates for the prevalence of severe wasting in the combined group compared to the other two groups in 2017 and 2018. There was no difference in the prevalence of moderate or severe wasting between the groups in 2019. The prevalence of stunting, low-MUAC-for-age or being underweight did not differ between groups for any of the three years. The prevalence of severe stunting was higher in the combined group compared to both other groups in 2018, and compared to RTS,S/AS01E alone in 2017; this observation does not have an obvious explanation and may be a chance finding. Overall, malnutrition was very common in this cohort, but declined over the study as the children became older.

Conclusions: Despite a high burden of malnutrition and malaria in the study populations, and a major reduction in the incidence of malaria in children receiving both interventions, this had only a modest impact on nutritional status. Therefore, other interventions are needed to reduce the high burden of malnutrition in these areas.

Trial registration: https://www.clinicaltrials.gov/ct2/show/NCT03143218 , registered 8th May 2017.

Keywords: Burkina Faso; Malaria; Mali; Nutrition; RTS,S/AS01E; Seasonal malaria chemoprevention.

Conflict of interest statement

OOA is an employee of the GSK group of companies and reports ownership of shares and/or restricted shares of the GSK group of companies. None of the other authors declare any competing interests.

© 2022. The Author(s).

Figures

Fig. 1

Study design. ETS survey, end of transmission season survey. Adapted from Chandramohan et al. [5]

Fig. 2

CONSORT Chart. Children who did not attend the first intervention contact (vaccine dose 1) were considered to have refused to participate in the trial. ETS, End of Transmission Season Survey; LFTU, lost-to-follow-up. All children that were seen at the ETS survey had their weight, height and MUAC recorded. *travelled denotes children who had temporarily travelled away from the study area at the time of the exit census but who had not permanently migrated. Adapted from Chandramohan et al. [5]

Fig. 3

Prevalence of key nutritional outcomes in study children in Burkina Faso and Mali over the study period 2017–2019

Fig. 4

Prevalence of moderate (a) and severe (b) nutritional outcomes in study children between study arms (SMC, RTS,S/AS01E and combined SMC + RTS,S/AS01) in Burkina Faso and Mali over the study period 2017–2019