Serologic responses to SARS-CoV-2 infection among hospital staff with mild disease in eastern France.

BACKGROUND

The serologic response of individuals with mild forms of SARS-CoV-2 infection is poorly characterized.

METHODS

Hospital staff who had recovered from mild forms of PCR-confirmed SARS-CoV-2 infection were tested for anti-SARS-CoV-2 antibodies using two assays: a rapid immunodiagnostic test (99.4% specificity) and the S-Flow assay (~99% specificity). The neutralizing activity of the sera was tested with a pseudovirus-based assay.

FINDINGS

Of 162 hospital staff who participated in the investigation, 160 reported SARS-CoV-2 infection that had not required hospital admission and were included in these analyses. The median time from symptom onset to blood sample collection was 24 days (IQR: 21-28, range 13-39). The rapid immunodiagnostic test detected antibodies in 153 (95.6%) of the samples and the S-Flow assay in 159 (99.4%), failing to detect antibodies in one sample collected 18 days after symptom onset (the rapid test did not detect antibodies in that patient). Neutralizing antibodies (NAbs) were detected in 79%, 92% and 98% of samples collected 13-20, 21-27 and 28-41 days after symptom onset, respectively (P = 0.02).

INTERPRETATION

Antibodies against SARS-CoV-2 were detected in virtually all hospital staff sampled from 13 days after the onset of COVID-19 symptoms. This finding supports the use of serologic testing for the diagnosis of individuals who have recovered from SARS-CoV-2 infection. The neutralizing activity of the antibodies increased overtime. Future studies will help assess the persistence of the humoral response and its associated neutralization capacity in recovered patients.

FUNDINGS

The funders had no role in study design, data collection, interpretation, or the decision to submit the work for publication.

Informations de copyright

Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.

Déclaration de conflit d'intérêts

Declaration of Competing Interest SFK, YM, RG, LT, FA, PS, CSM, NC, AB, AV, NL, MM, NM, DR.., BH, JDS and AF have no competing interest to declare. PC is the founder and CSO of TheraVectys. LG, IS, TB, and OS are holder of a provisional patent on the S-Flow assay. Dr. Schwartz has a patent "Methods and products for serological analysis of SARS-COV-2 Infection" pending on the S-Flow assay. Dr. Rey reports grants and personal fees from Mylan, personal fees from ViiV Healthcare, grants from Gilead, grants from Abbvie, outside the submitted work.