Long-term monitoring of SARS-CoV-2 seroprevalence and variants in Ethiopia provides prediction for immunity and cross-immunity

• Published in: Nature communications Vol. 15; no. 1; p. 3463
• Main Authors: Merkt, Simon, Ali, Solomon, Gudina, Esayas Kebede, Adissu, Wondimagegn, Gize, Addisu, Muenchhoff, Maximilian, Graf, Alexander, Krebs, Stefan, Elsbernd, Kira, Kisch, Rebecca, Betizazu, Sisay Sirgu, Fantahun, Bereket, Bekele, Delayehu, Rubio-Acero, Raquel, Gashaw, Mulatu, Girma, Eyob, Yilma, Daniel, Zeynudin, Ahmed, Paunovic, Ivana, Hoelscher, Michael, Blum, Helmut, Hasenauer, Jan, Kroidl, Arne, Wieser, Andreas
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 24.04.2024; Nature Publishing Group; Nature Portfolio
• Subjects: 101/1; 45/91; 631/326/596/4130; 692/699/255/2514; 692/700/478/174; Adolescent; Adult; Aged; Antibodies; Antibodies, Viral - blood; Antibodies, Viral - immunology; Child; Child, Preschool; COVID-19; COVID-19 - epidemiology; COVID-19 - immunology; COVID-19 - prevention & control; COVID-19 - virology; COVID-19 Vaccines - immunology; Data collection; Ethiopia - epidemiology; Female; Humanities and Social Sciences; Humans; Immunity; Male; Mathematical models; Middle Aged; multidisciplinary; Population studies; Reinfection - epidemiology; Reinfection - immunology; Reinfection - virology; Retrospective Studies; SARS-CoV-2 - genetics; SARS-CoV-2 - immunology; Science; Science (multidisciplinary); Sequences; Seroepidemiologic Studies; Serology; Severe acute respiratory syndrome coronavirus 2; Vaccination; Young Adult; Ethiopia
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-024-47556-2

Under-reporting of COVID-19 and the limited information about circulating SARS-CoV-2 variants remain major challenges for many African countries. We analyzed SARS-CoV-2 infection dynamics in Addis Ababa and Jimma, Ethiopia, focusing on reinfection, immunity, and vaccination effects. We conducted an antibody serology study spanning August 2020 to July 2022 with five rounds of data collection across a population of 4723, sequenced PCR-test positive samples, used available test positivity rates, and constructed two mathematical models integrating this data. A multivariant model explores variant dynamics identifying wildtype, alpha, delta, and omicron BA.4/5 as key variants in the study population, and cross-immunity between variants, revealing risk reductions between 24% and 69%. An antibody-level model predicts slow decay leading to sustained high antibody levels. Retrospectively, increased early vaccination might have substantially reduced infections during the delta and omicron waves in the considered group of individuals, though further vaccination now seems less impactful. Detailed data on SARS-CoV-2 dynamics in Africa remain limited. Here, the authors use longitudinal serology and SARS-CoV-2 sequencing data from Ethiopia between August 2020 and July 2022 to characterise circulating variants, identify infection pathways, and explore cross-immunity properties.