Rethinking the evidence on COVID-19 in Africa.

The COVID-19 pandemic was predicted to cause substantial mortality in Africa. However, some countries in Africa had a striking absence of overwhelmed hospitals and low reported mortality. The marked contrast with the overwhelmed hospitals and high mortality seen in Europe and other high-income settings was regarded as puzzling and a paradox. In this Review, we reflect on possible explanations for the paradox with particular reference to observations made on the ground in Kenya. The evidence is inconsistent with reduced viral transmission or poor surveillance as primary explanations for the discrepancy. Population age structure is an important but incomplete explanation of the epidemiology. Due to the high prevalence of asymptomatic infection, low mortality, and evidence of reduced inflammatory responses, we hypothesise that some populations in Africa might have reduced susceptibility to symptomatic COVID-19. The reduced inflammatory responses might result from immunoregulation or cross-reactive, pre-pandemic cellular immunity, although the evidence is not definitive. Local data are essential to develop public health policies that align with the reality on the ground rather than external perceptions.