The Huanan Market Origin of SARS-CoV-2 is unlikely: The ancestral lineage containing specimen appears to have arisen from laboratory contamination

<p>&bull;&nbsp;There is universal agreement that the lineage B/L is not the ancestral SARS-CoV-2; lineage A/S is the most ancestral lineage<br> &bull;&nbsp;Until the Gao paper, no lineage A/S virus was identified at the Huanan Market, making the market an unlikely origin for the pandemic<br> &bull;&nbsp;The Gao paper found one specimen, A20, with both lineage A/S and B/L<br> &bull;&nbsp;The lineage B/L reads in A20 and the specimen Ct matched the expected findings<br> &bull;&nbsp;The lineage A/S reads were anomalously high compared to the Ct and meet the definition of a statistical outlier<br> &bull;&nbsp;The SARS-CoV-2 reads from the A20 sample also had two SNVs not seen in GISAID sequences until at least 60-90 days after the specimen was collected from the market<br> &bull;&nbsp;This analysis supports a finding that the ancestral lineage A/S virus sequences in sample A20 were not present on the glove on January 1, 2020 when the sample was collected but instead arose by inadvertent laboratory contamination later, probably during metagenomic sequencing</p> <p>The absence of an unimpeachable ancestral lineage specimen at the Hunan Market makes it unlikely the market was the origin of the pandemic.</p>