Evaluation of a fully automated high-throughput SARS-CoV-2 multiplex qPCR assay with build-in screening functionality for DelHV69/70- and N501Y variants such as B.1.1.7 (preprint)

ABSTRACT

1BackgroundNew SARS-CoV-2 variants with increased transmissibility, like B.1.1.7 from England or B1.351 from South Africa, have caused considerable concern worldwide. In order to contain the spread of these lineages, it is of utmost importance to have rapid, sensitive and high-throughput detection methods at hand. MethodsAnalytical sensitivity was assessed for both wild-type SARS-CoV-2 and B.1.1.7 lineage by serial dilution. A total of 141 clinical samples were subjected to the test and results compared to a commercial manual typing-PCR assay and NGS. ResultsThe multiplex assay is highly sensitive for detection of SARS-CoV-2 RNA in clinical samples, with an LoD of 25.82 cp/ml (CI 11.61 - 57.48). LoDs are slightly higher for the HV68/70 deletion (111.36 cp/ml; CI 78.16 - 158.67) and the N501Y SNP (2548.04 cp/ml, CI 1592.58 - 4076.73). A total of 141 clinical samples were tested with the assay, including 16 samples containing SARS-CoV-2 of the B.1.1.7 lineage. Three non-B.1.1.7 samples contained a HV69/70 deletion. All were correctly identified by the multiplex assay. ConclusionWe describe here a highly sensitive, fully automated multiplex PCR assay for the simultaneous detection of del-HV69/70 and N501Y that can distinguish between lineages B.1.1.7 and B1.351. The assay allows for high-throughput screening for relevant variants in clinical samples prior to sequencing.