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Hard Science on the Covid-19 Pandemic [1]

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Date: 2023-02-27  

For those like me who wish to nerd out on this, the two critical papers (abstracts included) at this time are:

The molecular epidemiology of multiple zoonotic origins of SARS-CoV-2

www.science.org/…

“Understanding the circumstances that lead to pandemics is important for their prevention. We analyzed the genomic diversity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) early in the coronavirus disease 2019 (COVID-19) pandemic. We show that SARS-CoV-2 genomic diversity before February 2020 likely comprised only two distinct viral lineages, denoted “A” and “B.” Phylodynamic rooting methods, coupled with epidemic simulations, reveal that these lineages were the result of at least two separate cross-species transmission events into humans. The first zoonotic transmission likely involved lineage B viruses around 18 November 2019 (23 October to 8 December), and the separate introduction of lineage A likely occurred within weeks of this event. These findings indicate that it is unlikely that SARS-CoV-2 circulated widely in humans before November 2019 and define the narrow window between when SARS-CoV-2 first jumped into humans and when the first cases of COVID-19 were reported. As with other coronaviruses, SARS-CoV-2 emergence likely resulted from multiple zoonotic events.”



The Huanan Seafood Wholesale Market in Wuhan was the early epicenter of the COVID-19 pandemic

www.science.org/…

”Understanding how severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in 2019 is critical to preventing future zoonotic outbreaks before they become the next pandemic. The Huanan Seafood Wholesale Market in Wuhan, China, was identified as a likely source of cases in early reports, but later this conclusion became controversial. We show here that the earliest known COVID-19 cases from December 2019, including those without reported direct links, were geographically centered on this market. We report that live SARS-CoV-2–susceptible mammals were sold at the market in late 2019 and that within the market, SARS-CoV-2–positive environmental samples were spatially associated with vendors selling live mammals. Although there is insufficient evidence to define upstream events, and exact circumstances remain obscure, our analyses indicate that the emergence of SARS-CoV-2 occurred through the live wildlife trade in China and show that the Huanan market was the epicenter of the COVID-19 pandemic.”



Unfortunately, the authors handwave on the most significant flaw in the wet-market origin theory — the earliest SARS-CoV-2 sequences available came from people who were proximate to the market, but had no direct connection to it — and all the later samples in the market, both from humans and animals, are descendants of those early strains. (A point that has been known since the earliest phylogenies appeared in early 2020). In other words, it is clear that the market was the principle locus of early transmission, but it is unknown whether or not the pandemic originated in the market.

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[1] Url: https://www.dailykos.com/stories/2023/2/27/2155328/-Hard-Science-on-the-Covid-19-Pandemic

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