Materials and methods
A cross-sectional study was performed in 10 of 14 villages in Kibera informal settlement, Kenya’s largest slum community, in August 2021, before general vaccine roll-out. Participants were age one year and above with no symptoms of COVID-19. Capillary blood samples were tested using the Standard Q COVID-19 IgM/IgG Combo rapid test, Platelia SARS-CoV-2 Total Ab (IgM/IgG/IgA) Assay, and Wantai Total Ab (IgM/IgG/IgA) ELISA for SARS-CoV-2 which served as the reference test.