Clinical, virologic and immunologic features of a mild case of SARS-CoV-2 reinfection

• Authors: Pauline Vetter, Geneva Centre for Emerging Viral Diseases; Samuel Cordey, Laboratory of Virology, Geneva, Switzerland; Manuel Schibler, Geneva Centre for Emerging Viral Diseases; Laure Vieux, Division of Occupational Medicine, Geneva; Lena Despres, Division of Occupational Medicine, Geneva; Florian Laubscher, Geneva Centre for Emerging Viral Diseases, Geneva; Diego O Andrey, Geneva Centre for Emerging Viral Diseases, Geneva; Romain Martischang, Geneva University Hospitals; Stephan Harbarth, Geneva University Hospitals & Faculty of Medicine; Clémence Cuvelier, Geneva University Hospitals; Meriem Bekliz, Geneva Centre for Emerging Viral Diseases; Isabella Eckerle, Geneva Centre for Emerging Viral Diseases; Claire-Anne Siegrist, Geneva Centre for Emerging Viral Diseases; Arnaud M Didierlaurent, Geneva Centre for Emerging Viral Diseases; Christiane S Eberhardt, Emory University; Benjamin Meyer, Centre for Vaccinology, Geneva, Switzerland; Laurent Kaiser, Geneva Centre for Emerging Viral Diseases
• Journal Title: CLINICAL MICROBIOLOGY AND INFECTION
• Volume: Volume 27, Number 5
• Publisher: Elsevier | 2021-05-01
• Type of Work: Article | Final Publisher PDF
• Publisher DOI: http://doi.org/10.1016/j.cmi.2021.02.010
• Subjects: Health Sciences, Pathology; Health Sciences, Immunology
• Keywords: COVID-19; Immunity; Reinfection; SARS-CoV-2; Sequencing

Abstract

Objectives To report a case of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reinfection 6 months after the first infection in a young healthy female physician. Both episodes led to mild coronavirus disease 2019 (COVID-19). Methods SARS-CoV-2 infections were detected by real-time reverse transcriptase PCR (RT-PCR) on nasopharyngeal specimens. Reinfection was confirmed by whole-genome sequencing. Kinetics of total anti-S receptor binding domain immunoglobulins (Ig anti–S RBD), anti-nucleoprotein (anti-N) and neutralizing antibodies were determined in serial serum samples retrieved during both infection episodes. Memory B-cell responses were assessed at day 12 after reinfection. Results Whole-genome sequencing identified two different SARS-CoV-2 genomes both belonging to clade 20A, with only one nonsynonymous mutation in the spike protein and clustered with viruses circulating in Geneva (Switzerland) at the time of each of the corresponding episodes. Seroconversion was documented with low levels of total Ig anti–S RBD and anti-N antibodies at 1 month after the first infection, whereas neutralizing antibodies quickly declined after the first episode and then were boosted by the reinfection, with high titres detectable 4 days after symptom onset. A strong memory B-cell response was detected at day 12 after onset of symptoms during reinfection, indicating that the first episode elicited cellular memory responses. Conclusions Rapid decline of neutralizing antibodies may put medical personnel at risk of reinfection, as shown in this case. However, reinfection leads to a significant boosting of previous immune responses. Larger cohorts of reinfected subjects with detailed descriptions of their immune responses are needed to define correlates of protection and their duration after infection.