SARS-CoV-2 Neutralizing Responses in Various Populations, at the Time of SARS-CoV-2 Variant Virus Emergence: Evaluation of Two Surrogate Neutralization Assays in Front of Whole Virus Neutralization Test

• Published in: Life (Basel, Switzerland) Switzerland), 2022-12, Vol.12 (12), p.2064
• Main Authors: Marot, Stephane, Bocar Fofana, Djeneba, Flandre, Philippe, Malet, Isabelle, Zafilaza, Karen, Leducq, Valentin, Vivien, Diane, Mrabet, Sarah, Poignon, Corentin, Calvez, Vincent, Morand-Joubert, Laurence, Marcelin, Anne-Geneviève, Gozlan, Joel
• Format: Article
• Language: English
• Subjects: ACE2; Angiotensin-converting enzyme 2; Antibodies; Antigens; Assaying; Comparative analysis; Coronaviruses; COVID-19; COVID-19 vaccines; Enzyme-linked immunosorbent assay; Functional analysis; Gene expression; Health aspects; Immune response; Immunization; Immunoassay; Immunological research; Infection; Infections; mRNA; mRNA vaccines; Neutralization; neutralization surrogate assays; Neutralizing; neutralizing antibodies; Pandemics; Proteins; RNA; SARS-CoV-2; SARS-CoV-2 variants; Severe acute respiratory syndrome coronavirus 2; Vaccination; Vaccines; Viral antibodies; Viral diseases; Viruses
• ISSN: 2075-1729; 2075-1729
• DOI: 10.3390/life12122064

The SARS-CoV-2 neutralizing antibodies response is the best indicator of effective protection after infection and/or vaccination, but its evaluation requires tedious cell-based experiments using an infectious virus. We analyzed, in 105 patients with various histories of SARS-CoV-2 infection and/or vaccination, the neutralizing response using a virus neutralization test (VNT) against B.1, Alpha, Beta and Omicron variants, and compared the results with two surrogate assays based on antibody-mediated blockage of the ACE2-RBD interaction (Lateral Flow Boditech and ELISA Genscript). The strongest response was observed for recovered COVID-19 patients receiving one vaccine dose. Naïve patients receiving 2 doses of mRNA vaccine also demonstrate high neutralization titers against B.1, Alpha and Beta variants, but only 34.3% displayed a neutralization activity against the Omicron variant. On the other hand, non-infected patients with half vaccination schedules displayed a weak and inconstant activity against all isolates. Non-vaccinated COVID-19 patients kept a neutralizing activity against B.1 and Alpha up to 12 months after recovery but a decreased activity against Beta and Omicron. Both surrogate assays displayed a good correlation with the VNT. However, an adaptation of the cut-off positivity was necessary, especially for the most resistant Beta and Omicron variants. We validated two simple and reliable surrogate neutralization assays, which may favorably replace cell-based methods, allowing functional analysis on a larger scale.