February 16, 2021

S-Variant SARS-CoV-2 Lineage B1.1.7 Is Associated with Significantly Higher Viral Loads in Samples Tested by ThermoFisher TaqPath RT-QPCR

Category: Article Summary

Topic: Transmission

Keywords (Tags): immunity, variants

Individuals infected with the SARS-CoV-2 B.1.1.7 variant (first described in the UK) may have considerably higher viral loads, which could potentially explain the higher transmissibility of this variant. Analysis of 641 SARS-CoV-2 PCR positive samples in the UK from October to November 2020 showed that samples suspected to have the B.1.1.7 variant, identified by a unique test result profile in which the S-gene is not detected (i.e. S-gene target failure or SGTF), had lower cycle threshold (Ct) counts. Significantly more SGTF samples had higher inferred viral loads between 10⁷ to 10⁸, which the authors suggest could translate to median viral loads 10,000-fold higher than non-SGTF samples.

Kidd et al. (Feb 13, 2021). S-Variant SARS-CoV-2 Lineage B1.1.7 Is Associated with Significantly Higher Viral Loads in Samples Tested by ThermoFisher TaqPath RT-QPCR. The Journal of Infectious Diseases. https://doi.org/10.1093/infdis/jiab082