Lessons learned: A look back at the performance of nine COVID-19 serologic assays and their proposed utility.

BACKGROUND: Serologic assays for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been proposed to assist with the acute diagnosis of infection, support epidemiological studies, identify convalescent plasma donors, and evaluate vaccine response. METHODS: We report an evaluation of nine serologic assays: Abbott (AB) and Epitope (EP) IgG and IgM, EUROIMMUN (EU) IgG and IgA, Roche anti-N (RN TOT) and anti-S (RS TOT) total antibody, and DiaSorin (DS) IgG. We evaluated 291 negative controls (NEG CTRL), 91 PCR positive (PCR POS) patients (179 samples), 126 convalescent plasma donors (CPD), 27 healthy vaccinated donors (VD), and 20 allogeneic hematopoietic stem cell transplant (HSCT) recipients (45 samples). RESULTS: We observed good agreement with the method performance claims for specificity (93-100%) in NEG CTRL but only 85% for EU IgA. The sensitivity claims in the first 2 weeks of symptom onset was lower (26-61%) than performance claims based on > 2 weeks since PCR positivity. We observed high sensitivities (94-100%) in CPD except for AB IgM (77%), EP IgM (0%). Significantly higher RS TOT was observed for Moderna vaccine recipients then Pfizer (p-values < 0.0001). A sustained RS TOT response was observed for the five months following vaccination. HSCT recipients demonstrated significantly lower RS TOT than healthy VD (p < 0.0001) at dose 2 and 4 weeks after. CONCLUSIONS: Our data suggests against the use of anti-SARS-CoV-2 assays to aid in acute diagnosis. RN TOT and RS TOT can readily identify past-resolved infection and vaccine response in the absence of native infection. We provide an estimate of expected antibody response in healthy VD over the time course of vaccination for which to compare antibody responses in immunosuppressed patients.

How SARS-CoV-2 Transformed the Clinical Laboratory: Challenges and Lessons Learned.

The COVID-19 pandemic has made a devastating impact on global health and continues to challenge healthcare infrastructure and delivery. The clinical laboratories were no exception as they are responsible for diagnostic testing that dictates many clinical, infection control, and public health decisions. Information technology and laboratory management tools are critical assets for maintaining and adapting operations in response to crises. When utilized effectively, they promote the integration between the clinical laboratory specialties (e.g., chemistry, hematology, microbiology, and molecular pathology). During the COVID-19 pandemic, our systems and processes were strained due to high testing volumes, demand for rapid turnaround times, supply chain constraints, and constantly evolving testing algorithms and result interpretations as our knowledge of the virus and of diagnostics increased over time. In this report, we describe those challenges and subsequent adaptations made by each clinical laboratory section. We hope these details help to provide potential solutions and approaches for other hospitals facing COVID-19 surges or other future pandemics.