Longitudinal assessment of anti-SARS-CoV-2 antibody dynamics and clinical features following convalescence from a COVID-19 infection

Introduction: The longevity of antibody levels against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the duration of immunity are current topics of major scientific interest. Antibody kinetics during the acute phase are well studied, whereas the long-term kinetics are yet to be determined, with contradictory results from the studies to date. Here, we present a longitudinal analysis of the serological responses to a SARS-CoV-2 infection following convalescence and the association with postCOVID syndrome (PCS). Materials and methods: A total of 237 serum samples were prospectively collected from 61 participants who had had a SARS-CoV-2 infection, which was confirmed using quantitative reverse-transcription polymerase chain reaction (qRT-PCR). For each participant, anti-nucleocapsid (N) and anti-spike subunit 1 receptor binding domain (RBD/S1) immunoglobulin (Ig) levels were regularly determined over a period of 8 months. COVID-19-associated symptoms were assessed using a standardized questionnaire at study entry and again after 6 months. Results: Antibodies were detectable in 56 of the 61 participants. No substantial decline in anti-SARS-CoV2 pan-Ig levels was observed for the duration of the follow-up period. Antibody levels correlated positively with the disease severity, body mass index, fever, and smoking status. It was found that 46.8% of the participants suffered from PCS, with olfactory and gustatory dysfunctions being the most commonly reported symptoms. Conclusion: The results demonstrate stable anti-SARS-CoV-2 antibody titers and thus may indicate a longlasting immunity. The results are in line with recently published data and provide further insight concerning asymptomatic to mildly-affected patients, the association with clinical features, and the frequency of PCS. (c) 2021 The Authors. Published by Elsevier Ltd on behalf of International Society for Infectious Diseases. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-ncnd/4.0/).

Automated summary

This study provides insight into the long-term antibody response to SARS-CoV-2 infection, with stable antibody titers observed over an 8-month period. Nearly half of the participants experienced postCOVID syndrome, with olfactory and gustatory dysfunctions being the most commonly reported symptoms.