Comparing Results of Five SARS-CoV-2 Antibody Assays Before and After the First Dose of ChAdOx1 nCoV-19 Vaccine among Health Care Workers

Abstract

Reliable results of serologic positivity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody before and after AstraZeneca (AZ) vaccination are essential to estimate the efficacy of vaccination. We assessed the positivity rates and associated factors using five SARS-CoV-2 antibody assays. A total of 228 paired serum samples (456 samples) were obtained from 228 participants. After baseline sampling, the second sampling was conducted between 11-28 days after the first dose of AZ. Sera were tested using five SARS-CoV-2 antibody assays, including two surrogate virus neutralization tests. A questionnaire on symptom, severity, and duration of adverse reactions was completed by all participants. The overall positive rates for SARS-CoV-2 antibody were 84.6% for Roche, 92.5% for Abbott, 75.4% for Siemens, 90.7% for SD Biosensor, and 66.2% for GenScript assays after the first dose of AZ vaccination. The positive rates and antibody titer of sera obtained between 21-28 days were significantly higher than those obtained between 11-20 days in all five assays. More severe and longer duration of adverse reactions were related to higher SARS-CoV-2 antibody levels. The agreements and correlations among the applied assays were substantial (к=0.73-0.95) and strong (ρ=0.83-0.91). A single dose of AZ vaccination led to high positivity rates based on the five assays. Days after vaccination and adverse reactions could help estimate serologic conversions. The results should be interpreted cautiously considering the applied assays and cutoffs. Our findings could inform decisions regarding vaccination and laboratory settings and, thus, contribute to the control of the spread of SARS-CoV-2 infection.

Booster and anergic effects of the Covishield vaccine among healthcare workers in South India

“…Overall, the responder rate to Covishield was 83% on day 14, 98% on day 28 after the first dose, and 100% on day 14 after the second dose. Our results were similar to other studies after the first dose of ChAdOx1 [8,9].…”

Comparison of the Results of Five SARS-CoV-2 Antibody Assays before and after the First and Second ChAdOx1 nCoV-19 Vaccinations among Health Care Workers: a Prospective Multicenter Study

“…Finally, 218 samples were collected, aliquoted, and stored at −70°C until further use. The results for the baseline ( n = 228) and second samples ( n = 228) used in our previous study ( 4 ) were deposited in a public database (Harvard Dataverse) ( 9 ) and extracted for this study.…”

“…Serum samples were assessed using the following five SARS-CoV-2 antibody assays: (i) Elecsys anti-SARS-CoV-2 S total antibody assay on the Cobas e801 platform (Roche Diagnostics, Mannheim, Germany); (ii) SARS-CoV-2 IgG II Quant on the Alinity i platform (Abbott Laboratories Abbott Park, IL, USA); (iii) SARS-CoV-2 IgG assay on the Atellica platform (Siemens, Munich, Germany); (iv) STANDARD E SARS-CoV-2 neutralizing antibody (nAb) enzyme-linked immunosorbent assay (ELISA) kit (SD Biosensor, Suwon, South Korea); and (v) cPass SARS-CoV-2 neutralization antibody detection kit (GenScript, NJ, USA). SD Biosensor ELISA and GenScript ELISA were conducted using the Epoch microplate spectrophotometer (BioTek Instruments, Winooski, VT, USA) and ELx50 filter microplate washer (BioTek Instruments), similar to a previous study ( 4 ). Briefly, both the GenScript cPass SARS-CoV-2 neutralization antibody detection kit and the SD Biosensor STANDARD E SARS-CoV-2 nAb ELISA kit are surrogate virus neutralization tests.…”

“…Previously, our group investigated the antibody responses to a single dose of the AstraZeneca (AZ) (ChAdOx1 nCoV-19) vaccine (AstraZeneca, Lund, Sweden) using five SARS-CoV-2 antibody assays ( 4 ). That study showed a seroconversion rate ranging from 66.2% to 92.5% after first-dose vaccination, consistent with the rates in previous studies ( 5 , 6 ).…”

“…The five assays used in the study showed strong agreement and correlation with each other, but also some discrepancies. Therefore, we emphasized the importance of understanding the differences in the detailed detection principles of anti-SARS-CoV-2 immunoassays according to the various detection reagents and cutoff values ( 4 ). Furthermore, it has been reported that the AZ vaccine raises greater concerns about adverse effects compared to other vaccines ( 7 , 8 ).…”