Reduced amplification efficiency of the RNA-dependent-RNA-polymerase (RdRp) target enables tracking of the Delta SARS-CoV-2 variant using routine diagnostic tests

Routine SARS-CoV-2 surveillance in the Western Cape region of South Africa (January-August 2021) found a reduced PCR amplification efficiency of the RdRp gene target of the Seegene, Allplex 2019-nCoV diagnostic assay when detecting the Delta variant. We propose that this can be used as a surrogate for variant detection.