Residency of study participants (n = 745).

Africa has reported lower COVID-19 morbidity and mortality compared to other regions. Yet, the flat COVID-19 trajectory remains to be fully explained. Nigeria, Africa’s most populous country, accounted for less than 1% of global COVID-19 cases. The present study evaluated SARS-CoV-2 seroprevalence, vaccine uptake, and methodological differences in serological threshold setting among febrile patients attending peri-urban and urban clinics in Southern Nigeria. Between October 2022 and February 2023, 745 febrile participants were recruited from Owo (Ondo State) and Ikorodu (Lagos State). Serum samples were tested for IgG antibodies against wild-type and variant SARS-CoV-2 antigens using a multiplex bead-based antibody assay. Seropositivity was calculated using two classification boundary methods: (i) the conventional three standard deviations above the mean of negative controls (3STDV) and (ii) the open-source SeroNIST tool. Vaccine uptake and risk factors for exposure were assessed. Vaccine uptake was 66.0% and significantly higher in peri-urban Owo (80.2%) than urban Ikorodu (52.6%, p-value与全球其他地区相比，非洲报告的新型冠状病毒肺炎（COVID-19）发病率与死亡率均较低，但新冠疫情的平缓传播态势仍有待充分阐释。作为非洲人口最多的国家，尼日利亚的新冠确诊病例数占全球总数的比例不足1%。本研究针对尼日利亚南部城郊及城区诊所就诊的发热患者，评估了严重急性呼吸综合征冠状病毒2型（SARS-CoV-2）血清阳性率、疫苗接种率，以及血清学阈值设定的方法学差异。2022年10月至2023年2月期间，研究人员从翁多州奥沃市及拉各斯州伊科罗杜市招募了745名发热受试者。采用基于多重微球的抗体检测技术，对受试者的血清样本进行了针对野生型及变异株SARS-CoV-2抗原的免疫球蛋白G（IgG）抗体检测。研究采用两种分类界值法计算血清阳性率：(i) 以阴性对照均值加3倍标准差为阈值的常规方法（3STDV）；(ii) 开源工具SeroNIST。同时评估了疫苗接种率及感染暴露的危险因素。本次研究中总体疫苗接种率为66.0%，城郊奥沃市的疫苗接种率（80.2%）显著高于城区伊科罗杜市（52.6%，p值