Detection of SARS-CoV-2 variants by Abbott molecular, antigen, and serological tests (preprint)

Background Viral diversity presents an ongoing challenge for diagnostic tests, which need to accurately detect all circulating variants. The Abbott Global Surveillance program monitors severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) variants and their impact on diagnostic test performance. Objectives To evaluate the capacity of Abbott molecular, antigen, and serologic assays to detect the SARS-CoV-2 B.1.1.7, B.1.351 and the P.1 variants. Study design Virus variant culture stock dilutions (B.1.1.7, BEI NR-54011; B.1.351, BEI NR-54008 and 54009; P.1, BEI NR-54982) and clinical samples from patients with confirmed B.1.1.7 variant infection were run on the Abbott ID NOW COVID-19, m 2000 RealTi m e SARS-CoV-2, Alinity m SARS-CoV-2, and Alinity m Resp-4-Plex molecular assays; the BinaxNOW COVID-19 Ag Card and Panbio COVID-19 Ag Rapid Test Device; and the ARCHITECT/Alinity i SARS-CoV-2 IgG and AdviseDx IgM assays, Panbio COVID-19 IgG assay, and ARCHITECT/Alinity i AdviseDx SARS-CoV-2 IgG II assay. Results Cultured virus stocks and B.1.1.7 clinical samples were detected with molecular, antigen, and serologic assays in the expected ranges, confirming in silico predictions. The ratio between genome equivalents (GE) and calculated median tissue culture infectious dose (TCID 50 ) were 31-to 83-fold higher for B.1.1.7 cultures compared to B.1.351 and P.1 cultures, demonstrating that GE are more consistent units between cultures than TCID 50 . Conclusions Abbott molecular and antigen assays effectively detect B.1.1.7, B.1.351, and P.1 variant infections and Abbott serologic assays detect B.1.1.7 antibodies in patient sera. Future studies with SARS-CoV-2 virus cultures should use quantitative viral load values to compare detection of variants. Highlights Abbott SARS-CoV-2 molecular and antigen assays detect B.1.1.7, B.1.351, and P.1 variants Abbott SARS-CoV-2 antibody assays detect B.1.1.7 antibodies in recovered patient sera Quantitation of viral load in genome equivalents allows comparison of assay performance

Emission impacts of supply chain disruptions for COVID and China’s solid waste import ban (preprint)

Climate change will increase the frequency and severity of supply-chain disruptions and large-scale economic crises, also prompting environmentally-protective local policies. Here we use econometric time series analysis, inventory-driven price formation, dynamic material flow analysis, and gate-to-gate life cycle analysis to model the response of each copper supply chain actor to China’s solid waste import ban and the COVID-19 pandemic. We demonstrate that the economic changes associated with China’s solid waste import ban increase primary refining within China, offsetting the environmental benefits of decreased copper scrap refining and generating a cumulative increase in CO2e emissions of up to 35 Mt by 2040. Increasing China’s refined copper imports reverses this trend, decreasing CO2e emissions both in China (up to 300 Mt by 2040) and globally (up to 63 Mt). We test model outcome sensitivity to supply chain disruptions and economic crises using GDP, mining, and refining shocks associated with the COVID-19 pandemic, showing the results maintain impact magnitude alongside disruption effects.