Persisting adaptive immunity to SARS-CoV-2 in Lower Austria

Ladage, D.; Harzer, O.; Engel, P.; Winkler, H.; Braun, R.

The prevalence and persistence of adaptive immunity responses following a SARS-CoV-2 infection provides insights into potential population immunity. Adaptive immune responses comprise of antibody-based responses as well as T cell responses mainly addressing viruses and virus-infected human cells, respectively. A comprehensive analysis of both types of adaptive immunity is essential to follow population-based SARS-CoV-2-specific immunity. In this study, we assessed SARS-CoV-2-specific immunoglobulin A (IgA) levels, SARS-CoV-2-specific immunoglobulin G (IgG) levels, and SARS-CoV-2-specific T cell activities in patients who recovered from a COVID-19 infection in spring and autumn 2020. Here we observed a robust and stable SARS-CoV-2-specific adaptive immune response in both groups with persisting IgA and IgG levels as well as stable T cell activity. Moreover, there was a positive correlation of a lasting immune response with the severity of disease. Our data give evidence for a persisting adaptive immune memory, which suggest a continuing immunity for more than six months post infection.