Clinical presentation of severe malaria in children who received the RTS,S/AS01E malaria vaccine, seasonal malaria chemoprevention or the combination of both interventions in Burkina Faso and Mali.

BackgroundSevere Plasmodium falciparum malaria is a leading cause of death in sub-Saharan Africa, with most deaths occurring in children younger than five years of age. The RTS,S/AS01E (RTS,S) malaria vaccine delivered seasonally with Seasonal Malaria Chemoprevention (SMC) led to a two-third reduction in severe malaria and malaria deaths compared with either intervention given alone. The aim of this study was to assess the seasonal distribution and clinical presentation of children admitted in hospital with severe malaria who received RTS,S with or without SMC, and whether seasonal vaccination with RTS,S affected their distribution and clinical presentation. MethodsWe conducted a secondary ad-hoc analysis of hospital admissions in children aged 5 to 17 months of age when enrolled in the RTS,S + SMC trial in April 2017 in Hounde, Burkina Faso, and Bougouni, Mali, and who were followed until they reached five years of age. ResultsThree hundred and thirtythirty-seven serious adverse events were reported during the trial with 222 (65.9%) in Burkina Faso and 115 (34.1%) in Mali, and 48.1% (162/337) were due to severe malaria. The mean age of children with severe malaria was 2.9 years; 79.0% (128/162) of the cases occurred in children aged 3 years or less and 21.0% (34/162) in those aged 4 to 5 years. The most common presentation was severe anemia reported in 50% (81/162) of children, followed by repeated convulsions 25.3%, (41/162), prostration 11.1%, (18/162), hyperparasitaemia 8.0%, (13/162) and cerebral malaria 6.2%, (10/162). Severe malaria anemia was a more frequent form of severe malaria in children in the SMC alone arm 62.1%, (36/58) and lower in children in the SMC+ RTS,S arm 37.1%, (13/35), p=0.048. There was no significant difference in frequency of other clinical presentations between the study arms. Most severe malaria cases, 85.8% (139/162) occurred during the transmission season (July to December). ConclusionsSevere anaemia was the most common presentation of severe malaria and was most frequent in the SMC alone arm. Children aged 3 years or less were the most affected and almost all the cases occurred between July and December. Trial registrationClinicalTrials.gov, NCT04319380