SARS-CoV-2 immunoassays in a predominantly vaccinated population: Performances and qualitative agreements obtained with two analytical approaches and four immunoassays.
Vox Sang
; 119(6): 533-540, 2024 Jun.
Article
em En
| MEDLINE
| ID: mdl-38577957
ABSTRACT
BACKGROUND AND OBJECTIVES:
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serosurveys are typically analysed by applying a fixed threshold for seropositivity ('conventional approach'). However, this approach underestimates the seroprevalence of anti-nucleocapsid (N) in vaccinated individuals-who often exhibit a difficult-to-detect anti-N response. This limitation is compounded by delays between the onset of infection and sample collection. To address this issue, we compared the performance of four immunoassays using a new analytical approach ('ratio-based approach'), which determines seropositivity based on an increase in anti-N levels. MATERIALS ANDMETHODS:
Two groups of plasma donors and four immunoassays (Elecsys total anti-N, VITROS total anti-N, Architect anti-N Immunoglobulin G (IgG) and in-house total anti-N) were evaluated. First-group donors (N = 145) had one positive SARS-CoV-2 polymerase chain reaction (PCR) test result and had made two plasma donations, including one before and one after the PCR test (median = 27 days post-PCR). Second-group donors (N = 100) had made two plasma donations early in the Omicron wave.RESULTS:
Among first-group donors (97.9% vaccinated), sensitivity estimates ranged from 60.0% to 89.0% with the conventional approach, compared with 94.5% to 98.6% with the ratio-based approach. Among second-group donors, Fleiss's κ ranged from 0.56 to 0.83 with the conventional approach, compared with 0.90 to 1.00 with the ratio-based approach.CONCLUSION:
With the conventional approach, the sensitivity of four immunoassays-measured in a predominantly vaccinated population based on samples collected ~1 month after a positive test result-fell below regulatory agencies requirement of ≥95%. The ratio-based approach significantly improved the sensitivities and qualitative agreement among immunoassays, to the point where all would meet this requirement.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Vacinas contra COVID-19
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SARS-CoV-2
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COVID-19
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Anticorpos Antivirais
Limite:
Adult
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Revista:
Vox Sang
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
Canadá