Detection of antibodies against SARS-CoV-2 Spike Wild-Type and Gamma (P.1) variant after vaccination with ChAdOx1-S and BNT162b2 using an electrochemical immunosensor

Detection of antibodies against SARS-CoV-2 Spike Wild-Type and Gamma (P.1) variant after vaccination with ChAdOx1-S and BNT162b2 using an electrochemical immunosensor

• Autor
• Freddy Nunez
• Co-autores
• Ana de Castro , Vivian de Oliveira , wendel alves
• Resumo

•  SARS-CoV-2 variants have demonstrated high disease transmissibility, more disease severity, a remarkable decrease in antibody neutralization, decreased effectiveness of treatments, and diagnostic detection failure. Diagnostic methods based on electrochemical biosensors are promising alternatives to conventional laboratory tests to detect antibodies against SARS-CoV-2 variants and they can be a great tool, supporting the development of vaccines and evaluating the efficacy of different immunization programs. In this work, we used a label-free impedimetric biosensor based on zinc oxide nanorods (ZnONRs) coated onto the FTO electrode. The presence of the ZnONRs matrix provides a suitable biocompatible environment for the immobilization of biomolecules. The recombinant Spike protein SARS-CoV-2 WT ((LECC) of COPPE/Federal University of Rio de Janeiro) and SARS-CoV-2 P.1 variant (BEI Resources, NR-55307) was immobilized by physical adsorption. We evaluated clinical samples (1:500 v/v dilution). The control serum samples were collected from venous blood before the COVID-19 pandemic (n = 10). The ChAdOx1-S (Oxford–AstraZeneca) (n = 29) and BNT162b2 (Pfizer–BioNTech) (n = 29) venous blood were collected from vaccinated study participants who reported no previous infection with SARS-CoV-2 at least 28 days after the second immunization. Our results showed that the ZnONRS/Spike immunosensor could identify the induced antibody response against SARS-CoV-2 Spike P.1 protein stimulated by vaccination. The Rct signal is lower for the samples evaluated against Spike protein P.1 than for those evaluated against the viral wild-type (WT) S protein. The Rct signal was higher for the samples of individuals vaccinated with BNT162b2 compared to those vaccinated with ChAdOx1-S, indicating that the BNT162b2 vaccine has a greater capacity for vaccine-induced humoral response against the COVID-19 P.1 VoC. The data points under the determined cutoff suggest that Individuals vaccinated with ChAdOx1-S presented a lower ability to recognize the Spike protein from the SARS-CoV-2 P.1 variant than individuals vaccinated with BNT162b2. The ZnONRs/Spike WT immunosensor detection test presented an AUC of 0.9908 which was higher in comparison with the ZnONRs/Spike P.1 which presented an AUC of 0.9034, nevertheless, both values indicated the high accuracy of this assay

• Palavras-chave
• SARS-CoV-2 variants, SARS-CoV-2 vaccines, Zinc Oxide, Immunosensors
• Modalidade
• Pôster
• Área Temática
• Materiais Funcionais Avançados