On March 25, 2021, Springer Nature journal published another peer reviewed study on SARS-CoV-2 origins. It certificates the probable laboratory leak of the viral agent behind the COVID-19 pandemic. Authors Rossana Segreto, Yuri Deigin, Kevin McCairn, Alejandro Sousa, Dan Sirotkin, Karl Sirotkin, Jonathan J. Couey, Adrian Jones & Daoyu Zhang are largely members of Drastic team. Let’s see on which scientific and rational elements the article in question presses most to support the anthropogenic theory:
- Low rate of evolution in the early phase of transmission.
- The lack of evidence of recombination events.
- High pre-existing binding to human ACE2.
- A novel furin cleavage site insert.
- High human and mouse peptide mimicry.
No credible intermediate hosts
The peer reviewed study finds further strength from the observation that a year after the initial outbreak in Wuhan there is still no clear evidence of zoonotic transfer from a bat or other intermediate species. No evidence despite scientists analyzed 80,000 animal samples. The other 2 betacoronavirus’ epidemic that occurred in the past (SARS and MERS) demanded only a bunch of months.
Authors have also investigated the other possibilities expressed in the China-WHO cross-examination (including the cold chain hypothesis). They didn’t find concrete chances that pangolins and mustelids are intermediate species through which SARS-CoV-2 was transferred to humans. The other possibility of imported contaminated frozen food turned out same way as an extremely unlikely source.
Highlighting Andersen paper errors
The scientists further presented how, contrary to Andersen et al. supposition, there is no O-linked glycosylation on the neighboring residues of the S1/S2 junction, or at a significant level anywhere along the spike protein. No interaction of SARS-CoV-2 with a host immune system based on O-linked glycans can be claimed, and hence does not support the argument for natural evolution of SARS-CoV-2.
Currently we can say that this is the best scientific piece we have in support of the theory of a laboratory leak of the pathogen. Probably many others will arrive soon in order to favor the theory after the countless suppressions due to politicization. The important thing, we never forget, is to make sure that similar events due to gain-of-function studies never repeat.
Following the publication of the study, no scientist who has publicly exposed for supporting the zoonotic theory had the will to scientifically counter it. We strongly hope that the future is more harbinger of a healthy debate between the two currents of thought.