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Evaluation of residual humoral immune response against SARS-CoV-2 by a surrogate virus neutralization test (sVNT) 9 months after BNT162b2 primary vaccination()

The humoral response to SARS-CoV-2 vaccination has shown to be temporary, although may be more prolonged in vaccinated individuals with a history of natural infection. We aimed to study the residual humoral response and the correlation between anti-Receptor Binding Domain (RBD) IgG levels and antibo...

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Detalles Bibliográficos
Autores principales: Pezzati, Laura, Milazzo, Laura, Carrozzo, Giorgia, Kullmann, Cristina, Oreni, Letizia, Beltrami, Martina, Caronni, Stefania, Lai, Alessia, Caberlotto, Livio, Ottomano, Cosimo, Antinori, Spinello, Ridolfo, Anna Lisa
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Japanese Society of Chemotherapy, Japanese Association for Infectious Diseases, and Japanese Society for Infection Prevention and Control. Published by Elsevier Ltd. 2023
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10008091/
https://www.ncbi.nlm.nih.gov/pubmed/36914095
http://dx.doi.org/10.1016/j.jiac.2023.03.002
Descripción
Sumario:The humoral response to SARS-CoV-2 vaccination has shown to be temporary, although may be more prolonged in vaccinated individuals with a history of natural infection. We aimed to study the residual humoral response and the correlation between anti-Receptor Binding Domain (RBD) IgG levels and antibody neutralizing capacity in a population of health care workers (HCWs) after 9 months from COVID-19 vaccination. In this cross-sectional study, plasma samples were screened for anti-RBD IgG using a quantitative method. The neutralizing capacity for each sample was estimated by means of a surrogate virus neutralizing test (sVNT) and results expressed as the percentage of inhibition (%IH) of the interaction between RBD and the angiotensin-converting enzyme. Samples of 274 HCWs (227 SARS-CoV-2 naïve and 47 SARS-CoV-2 experienced) were tested. The median level of anti-RBD IgG was significantly higher in SARS-CoV-2 experienced than in naïve HCWs: 2673.2 AU/mL versus 610.9 AU/mL, respectively (p <0.001). Samples of SARS-CoV-2 experienced subjects also showed higher neutralizing capacity as compared to naïve subjects: median %IH = 81.20% versus 38.55%, respectively; p <0.001. A quantitative correlation between anti-RBD Ab and inhibition activity levels was observed (Spearman's rho = 0.89, p <0.001): the optimal cut-off correlating with high neutralization was estimated to be 1236.1 AU/mL (sensitivity 96.8%, specificity 91.9%; AUC 0.979). Anti-SARS-CoV-2 hybrid immunity elicited by a combination of vaccination and infection confers higher anti-RBD IgG levels and higher neutralizing capacity than vaccination alone, likely providing better protection against COVID-19.