Here's a comment from a discussion over at Unz.com:
Antibeast: Phylogenetic analyses have shown that the Wuhan ‘L’ strain is NOT ancestral to the Italian ‘G’ strain which has the D614G mutation in its spike S protein, causing the latter to become more infectious over time. The Wuhan ‘L’ strain does NOT have the D614G mutation in its spike S protein which explains its low rate of infectiousness thus leading to a lower number of Covid-19 cases in Wuhan, as compared to Italy. The attribution of Wuhan-1 arising inside of China is quite likely true, however the attribution of progenitor Covid is not needed to originate inside of China, that is only an inference that has not been established.
The Wuhan ‘L’ strain is attributed to have originated in Wuhan while the Italian ‘G’ strain is attributed to have originated in Italy. Both share a common ancestral strain which has yet to be attributed to its place of origin. Here’s an article discussing the significance of the D614G mutation in the Italian ‘G’ strain which caused the global Covid-19 pandemic: https://graphics.reuters.com/HEALTH-CORONAVIRUS/EVOLUTION/yxmpjqkdzvr/ G strains are now dominant around the world. One specific mutation, D614G, has become the most common variant. It is so named because one amino acid is changed from a D (aspartate) to a G (glycine) at the 614th position on the viral spike proteins, the structure that gives the virus its crown-like appearance. The rise of the G strains coincided with spikes in outbreaks of the virus around the world, with a clutch of new cases allowing the strains to invade new areas. The dominance of the G strains is illustrated by the data for Australia, Japan and Thailand. During Australia’s second wave of infections, G strains were present in almost all samples, indicating the country had effectively eliminated transmission of the earlier L and S strains through a series of social distancing measures. All of Australia’s second wave clusters were sparked by people who had returned from overseas and breaches in quarantine. The dominance of the G-strains becomes even more evident when looking at some countries with the most infections. The United States is leading the overall number of infections and deaths by far. The majority of infections and first, second, and third waves all coincide with the increase in samples showing three G strains. In India, a similar pattern can be observed as the constant increase in infections from June to September seemed to follow the curve of the G strain samples.
Empirical evidence suggests that travel bans and containment measures adopted against travelers from China during Jan-Feb 2020 helped stop the spread of the SARS-CoV-2 coronavirus as evidenced by the low number of Covid-19 cases involving the Wuhan ‘L’ strain outside of China. Scientific evidence has now proven that the Italian ‘G’ strain spread rapidly throughout the Western World during the same period precisely due to its D614G mutation which caused the global Covid-19 pandemic. As both the Wuhan ‘L’ strain and the Italian ‘G’ strain were known to have been discovered in December 2019, the question as to the origin of the SARS-CoV-2 coronavirus must perforce address the global spread of the ancestral strain prior to December 2019. This inquiry should not be limited to Wuhan but also expanded to Italy and elsewhere. |
That the SARS-COV2 viral outbreak in China in late 2019 was of the less infectious L Strain, not the G Strain that afflicted the rest of the world, would explain several otherwise curious facts; namely,
(1) that China contained the initial outbreak quickly and with very few deaths; and
As the author of the comment quoted above notes, that the global pandemic began with more than one viral strain raises new questions about the origin and global spread of SARS-COV2.
