Antibody persistency and trend post-SARS-CoV-2 infection at eight months

An improved understanding of the immunity offered by the antibodies developed against SARS-CoV-2 is critical for the development of diagnostic tests and vaccines. Our study aimed at the longitudinal analysis of antibody presence, persistence and its trend over a period of eight months in a group of COVID-19 recovered patients who tested positive by real-time quantitative PCR for SARS-CoV-2 in the period between the 18th and 30th of March, 2020. The subjects were divided into two groups based on disease severity: mild and moderately-severe. The MAGLUMI 2019-nCoV lgM/lgG chemiluminescent analytical system (CLIA) assay was used to analyse the antibody titres. Robust IgG antibody persistency was demonstrated in 76.7 % of the subjects (23 out of 30) at eight months post-infection. The results of this study highlight an important point in terms of the association between humoral immune response and disease severity. Patients who might have experienced a relatively moderate-severe infection may develop a robust immunity that could persist for a longer duration.