1. Omicron B.1.1.529 variant infections associated with severe disease are uncommon in a COVID-19 under-vaccinated, high SARS-CoV-2 seroprevalence population in MalawiResearch in context
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Upendo L. Mseka, Jonathan Mandolo, Kenneth Nyoni, Oscar Divala, Dzinkambani Kambalame, Daniel Mapemba, Moses Kamzati, Innocent Chibwe, Marc Y.R. Henrion, Kingsley Manda, Deus Thindwa, Memory Mvula, Bright Odala, Raphael Kamng'ona, Nelson Dzinza, Khuzwayo C. Jere, Nicholas Feasey, Antonia Ho, Abena S. Amoah, Melita Gordon, Todd D. Swarthout, Amelia Crampin, Robert S. Heyderman, Matthew Kagoli, Evelyn Chitsa-Banda, Collins Mitambo, John Phuka, Benson Chilima, Watipaso Kasambara, Kondwani C. Jambo, and Annie Chauma-Mwale
- Subjects
Omicron ,SARS-CoV-2 ,Anti-RBD antibodies ,COVID-19 ,Malawi ,Medicine (General) ,R5-920 - Abstract
Summary: Background: The B.1.1.529 (Omicron) variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in the fourth COVID-19 pandemic wave across the southern African region, including Malawi. The seroprevalence of SARS-CoV-2 antibodies and their association with epidemiological trends of hospitalisations and deaths are needed to aid locally relevant public health policy decisions. Methods: We conducted a population-based serosurvey from December 27, 2021 to January 17, 2022, in 7 districts across Malawi to determine the seroprevalence of SARS-CoV-2 antibodies. Serum samples were tested for antibodies against SARS-CoV-2 receptor binding domain using WANTAI SARS-CoV-2 Receptor Binding Domain total antibody commercial enzyme-linked immunosorbent assay (ELISA). We also evaluated COVID-19 epidemiologic trends in Malawi, including cases, hospitalisations and deaths from April 1, 2021 through April 30, 2022, collected using the routine national COVID-19 reporting system. A multivariable logistic regression model was developed to investigate the factors associated with SARS-CoV-2 seropositivity. Findings: Serum samples were analysed from 4619 participants (57% female; 60% aged 18–50 years), of whom 878/3794 (23%) of vaccine eligible adults had received a single dose of any COVID-19 vaccine. The overall assay-adjusted seroprevalence was 83.7% (95% confidence interval (CI), 79.3%–93.4%). Seroprevalence was lowest among children
- Published
- 2023
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