Fig 1. Reported COVID-19 cases among the general population and SARS-CoV-2 seroprevalence among study participants, by district.
The bars represent COVID-19 case among all persons in the district reported by Zambia National Public Health Institute and the lines represent the monthly SARS-CoV-2 seroprevalence among pregnant women attending antenatal care in the district during the study. Serologic testing was done using the Tetracore FlexImmArray SARS-CoV-2 Human IgG Antibody Test; a positive result was assigned if signal ratios ≥1.2 for all 3 assay targets (nucleocapsid [N], receptor-binding domain [RBD] of the spike protein, and N-RBD fusion). Seroprevalence was adjusted for assay performance (sensitivity = 89.8% and specificity = 100%) and error bars represent 95% confidence intervals.