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Neutralizing Activity of SARS-CoV-2 Antibodies in Patients with COVID-19 and Vaccinated Individuals

Authors :
Tatjana Vilibic-Cavlek
Vladimir Stevanovic
Snjezana Kovac
Ema Borko
Maja Bogdanic
Gorana Miletic
Zeljka Hruskar
Thomas Ferenc
Ivona Coric
Mateja Vujica Ferenc
Ljiljana Milasincic
Ljiljana Antolasic
Ljubo Barbic
Source :
Antibodies, Vol 12, Iss 4, p 61 (2023)
Publication Year :
2023
Publisher :
MDPI AG, 2023.

Abstract

Background: Serological diagnosis of COVID-19 is complex due to the emergence of different SARS-CoV-2 variants. Methods: 164 serum samples from (I) patients who recovered from COVID-19 (n = 62) as well as (II) vaccinated individuals (n = 52) and (III) vaccinated individuals who were infected with different SARS-CoV-2 variants after vaccination (n = 50) were included. All samples were tested using EIA (binding antibodies) and a virus neutralization test (VNT) using the Wuhan strain (NT antibodies). Group III was further tested with a VNT using the Alpha/Delta/Omicron strains. Results: The highest antibody index (AI) was observed in vaccinated individuals infected with COVID-19 (median AI = 50, IQR = 27–71) and the lowest in vaccinated individuals (median AI = 19, IQR = 8–48). Similarly, NT antibody titer was highest in vaccinated individuals infected with COVID-19 (median 128; IQR = 32–256) compared to vaccinated individuals (median 32, IQR = 4–128) and patients with COVID-19 (median 32, IQR = 8–64). The correlation between AI and NT titer was strongly positive in vaccinated individuals and moderately positive in patients with COVID-19. No significant correlation was observed in vaccinated individuals infected with COVID-19. In patients infected with Alpha and Delta, the lowest VNT positivity rate was for the Omicron variant (85.0%/83.3%). Patients infected with the Alpha variant showed the lowest NT titer for the Omicron variant (median titer 32) compared to the Wuhan/Delta variants (64/128). Patients infected with the Delta variant had the lowest NT titer to the Omicron variant (median 32), compared to the Wuhan/Alpha variants (64/128). Patients infected with the Omicron variant showed similar titers to the Delta/Wuhan variants (128) and higher to the Alpha variant (256). Conclusions: The cross-immunity to SARS-CoV-2 is lowest for the Omicron variant compared to the Alpha/Delta variants.

Details

Language :
English
ISSN :
12040061 and 20734468
Volume :
12
Issue :
4
Database :
Directory of Open Access Journals
Journal :
Antibodies
Publication Type :
Academic Journal
Accession number :
edsdoj.bb1f433b24de46ada0166ae2bf073bed
Document Type :
article
Full Text :
https://doi.org/10.3390/antib12040061