Comparison of Five Serological Assays for the Detection of SARS-CoV-2 Antibodies

Abstract

Serological assays can contribute to the estimation of population proportions with previous immunologically relevant contact with the Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2) virus. In this study, we compared five commercially available diagnostic assays for the diagnostic identification of SARS-CoV-2-specific antibodies. Depending on the assessed immunoglobulin subclass, recorded sensitivity ranged from 17.0% to 81.9% with best results for immunoglobulin G. Specificity with blood donor sera ranged from 90.2% to 100%, with sera from EBV patients it ranged from 84.3% to 100%. Agreement from fair to nearly perfect was recorded depending on the immunoglobulin class between the assays, the with best results being found for immunoglobulin G. Only for this immunoglobulin class was the association between later sample acquisition times (about three weeks after first positive PCR results) and positive serological results in COVID-19 patients confirmed. In conclusion, acceptable and comparable reliability for the assessed immunoglobulin G-specific assays could be shown, while there is still room for improvement regarding the reliability of the assays targeting the other immunoglobulin classes.

Spectrum Bias and Individual Strengths of SARS-CoV-2 Serological Tests—A Population-Based Evaluation

“…Therefore, both Roche assays can be proposed as a gold standard for dichotomous testing in a population-based setting. Our population-based results contradict the earlier findings by others reporting a sensitivity of 76% and non-determinable specificity for the COBAS_N based on convenience samples [31]. As their findings also strongly differ from the manufacturer's information [32], one might attribute those results to the time point of blood drawal (e.g., shortly after infection) or cohort composition [31].…”

“…Our population-based results contradict the earlier findings by others reporting a sensitivity of 76% and non-determinable specificity for the COBAS_N based on convenience samples [31]. As their findings also strongly differ from the manufacturer's information [32], one might attribute those results to the time point of blood drawal (e.g., shortly after infection) or cohort composition [31]. In contrast, all of our findings regarding sensitivity and specificity settle completely in line with the maufacturer's data as well as larger meta-analyses attributing a general sensitivity of approximately 80 to 90% as well as a specificity of well over 95% to ELISA-and CLIA-based assays [4,26].…”

Severe Acute Respiratory Syndrome Coronavirus-2 Antibody Seropositivity among Healthcare Workers Working in Coronavirus Disease Wards

“…She mainly worked while wearing PPE and retained a distance of more than 2 m from the COVID-19 patients. Since she was 6 weeks pregnant at the time of blood collection, the antibody test result was likely to be false positive [4,5].…”

Prevalence and Course of IgA and IgG Antibodies against SARS-CoV-2 in Healthcare Workers during the First Wave of the COVID-19 Outbreak in Germany: Interim Results from an Ongoing Observational Cohort Study

“…For IgA and IgG, a cutoff ratio <0.8 means a seronegative result, 0.8–1.1 means a borderline result and >1.1 a positive result. For IgA, the reported negative predictive value was between 0.975 and 100% and for IgG at 0.979–100%, respectively [ 13 , 18 ].…”