Comparative analysis of three laboratory based serological assays for SARS-CoV-2 in an Australian cohort

Comprehensive, comparative evaluation of 25 automated SARS-CoV-2 serology assays

IMPORTANCE

We have previously highlighted the fact that hundreds of SARS-CoV-2 serology tests were released months after the onset of the COVID-19 pandemic. Of the hundreds of studies investigating the test kits' performance, few were comparative reports, using the same comprehensive sample set across multiple tests. Recently, we reported a comparative assessment of 35 rapid diagnostic tests (RDTs) or microtiter plate enzyme immunoassays (EIA) for use in low- and middle-income countries, using a large sample set from individuals with a history of COVID-19. Only a few tests meet WHO Target Product Profile performance requirements. This study reports on the performance of a further 25 automated SARS-CoV-2 immunoassays using the same panel of samples. The results highlight the better analytical and clinical performance of automated serology test kits compared with RDTs, and the importance of independent comparative assessments to inform the use and procurement of these tests for both diagnostic and epidemiological investigations.

Diagnostic Value of a SARS-CoV-2 Rapid Test Kit for Detection of Neutralizing Antibodies as a Point-of-Care Surveillance Test

In the ongoing coronavirus disease 2019 (COVID-19) pandemic, antibody tests play an increasingly important role in detecting previous infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and monitoring of response to vaccinations. In particular, neutralizing antibodies have recently been demonstrated to be highly predictive of immune protection against symptomatic infection.

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

(1) Background: Healthcare workers (HCWs) are prone to intensified exposure to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection in the ongoing pandemic. We prospectively analyzed the prevalence of antibodies against SARS-CoV-2 in HCWs at baseline and follow up with regard to clinical signs and symptoms in two university hospitals in Brandenburg, Germany. (2) Methods: Screening for anti-SARS-CoV-2 IgA and IgG antibodies was offered to HCWs at baseline and follow up two months thereafter in two hospitals of Brandenburg Medical School during the first wave of the COVID-19 pandemic in Germany in an ongoing observational cohort study. Medical history and signs and symptoms were recorded by questionnaires and analyzed. (3) Results: Baseline seroprevalence of anti-SARS-CoV-2 IgA was 11.7% and increased to 15% at follow up, whereas IgG seropositivity was 2.1% at baseline and 2.2% at follow up. The rate of asymptomatic seropositive cases was 39.5%. Symptoms were not associated with general seropositivity for anti-SARS-CoV-2; however, class switch from IgA to IgG was associated with increased symptom burden. (4) Conclusions: The seroprevalence of antibodies against SARS-CoV-2 was low in HCWs but higher compared to population data and increased over time. Screening for antibodies detected a significant proportion of seropositive participants cases without symptoms.