Malaria as a Protection Factor Against Severe COVID-19 in the Democratic Republic of Congo (Palu-COVID)

In this study, the investigators will explore the reasons for the apparently lower proportion of severe COVID-19 cases in many sub-Sahara African countries. Indeed, despite fragile health care systems, the burden of COVID-19 on the African continent seems substantially lower than initially feared. Many potential reasons for this discrepancy have been formulated: the different population age structure, experience of African nations with previous pandemics, warmer climate, and genetic preposition. However, another compelling hypothesis is that of trained immunity by endemic pathogens, such as plasmodia. According to this hypothesis, innate immune activation by endemic pathogens would prime a more robust initial innate immune response to SARS-CoV-2 and could therefore protect against severe COVID-19.

To explore this, the investigators propose conducting a case-control study in Kinshasa, in the Democratic Republic of the Congo (DRC). Kinshasa is an area with mixed prevalence of malaria and the area in DRC most affected by COVID-19. In this setting, the investigators will compare cases of severe COVID-19 with controls that have non-severe COVID-19 and that are matched for age, sex, and health zone. The aim is to compare pre-existing immunity against malaria, both cellular and humoral between the two groups.