Preceding anti-spike IgG levels predicted risk and severity of COVID-19 during the Omicron-dominant wave in Santa Fe city, Argentina. (3rd November 2022)

• Record Type: Journal Article
• Authors: Eberhardt, Ayelen T.; Simoncini, Melina; Piña, Carlos; Galoppo, Germán; Parachú-Marco, Virginia; Racca, Andrea; Arce, Sofía; Viotto, Evangelina; Facelli, Florencia; Valli, Florencia; Botto, Cecilia; Scarpa, Leonardo; Junges, Celina; Palavecino, Cintia; Beccaria, Camila; Sklar, Diego; Mingo, Graciela; Genolet, Alicia; Muñoz de Toro, Mónica; Aimar, Hugo; Marignac, Verónica; Bossio, Juan Carlos; Armando, Gustavo; Fernández, Hugo; Beldomenico, Pablo M.
• Is Part Of: Epidemiology and infection. Volume 150(2022)
• Publication Date: 2022-11-03
• Subjects: Antibody titre -- disease severity -- humoral defences -- infection risk -- longitudinal study -- pre-exposure -- SARS-CoV-2; Communicable diseases -- Periodicals; Epidemiology -- Periodicals; 614.4
• DOI: 10.1017/S0950268822001716
• Languages: English
• ISSNs: 0950-2688

Abstract

Abstract: The SARS-CoV-2 Omicron variant has increased infectivity and immune escape compared with previous variants, and caused the surge of massive COVID-19 waves globally. Despite a vast majority (~90%) of the population of Santa Fe city, Argentina had been vaccinated and/or had been infected by SARS-CoV-2 when Omicron emerged, the epidemic wave that followed its arrival was by far the largest one experienced in the city. A serosurvey conducted prior to the arrival of Omicron allowed to assess the acquired humoral defences preceding the wave and to conduct a longitudinal study to provide individual-level real-world data linking antibody levels and protection against COVID-19 during the wave. A very large proportion of 1455 sampled individuals had immunological memory against COVID-19 at the arrival of Omicron (almost 90%), and about half (48.9%) had high anti-spike immunoglobulin G levels (>200 UI/ml). However, the antibody titres varied greatly among the participants, and such variability depended mainly on the vaccine platform received, on having had COVID-19 previously and on the number of days elapsed since last antigen exposure (vaccine shot or natural infection). A follow-up of 514 participants provided real-world evidence of antibody-mediated protection against COVID-19 during a period of high risk of exposure to an immune-escaping highly transmissible variant. Pre-wave antibody titres were strongly negatively associated with COVID-19 incidence and severity of symptoms during the wave. Also, receiving a vaccine shot during the follow-up period reduced the COVID-19 risk drastically (15-fold). These results highlight the importance of maintaining high defences through vaccination at times of high risk of exposure to immune-escaping variants.