8-11-20 Dr. Latham and Dr. Wilson on Sars2 origin:
As we showed too, the Shi lab had also won a grant to extend that work to whole live animals. They planned “virus infection experiments across a range of cell cultures from different species and humanized mice” with recombinant bat coronaviruses. …To learn more, especially about the reasonableness of this diagnosis, we arranged to have the whole Master’s thesis translated into English and are here making the translation available. To read it in full see the embedded document below (or download it here).
The six ill miners were admitted to the No. 1. School of Clinical Medicine, Kunming Medical University, in short succession in late April and early May 2012. Kunming is the capital of Yunnan province and 250 Km from Mojiang. Of the descriptions of the miners and their treatments, which include radiographs and numerous CAT scans, several features stand out:
1) From their admission to the hospital their doctors informed the “medical office” of a potential “outburst of disease” i.e. a potential epidemic outbreak. Thus the miners were treated for infections and not as if they had inhaled noxious gases or other toxins.
2) The symptoms (on admission) of the six miners were: a) dry cough, b) sputum, c) high fevers, especially shortly before death d) difficulty breathing, e) myalgia (sore limbs). Some patients had hiccoughs and headaches. (See Table 1). … …
6) A small number of remote meetings were held with researchers at other universities. One was with Zhong Nanshan at Sun Yat-Sen University, Guangdong. Zhong is the Chinese hero of the SARS epidemic, a virologist, and arguably the most famous scientist in China.
7) Samples from the miners were later sent to the WIV in Wuhan and to Zhong Nanshan, further confirming that viral disease was strongly suspected. Some miners did test positive for coronavirus (the thesis is unclear on how many).
8) The source of infection was concluded to be Rhinolophus sinicus, a horseshoe bat and the ultimate conclusion of the thesis reads “the unknown virus lead to severe pneumonia could be: The SARS-like-CoV from the Chinese rufous horseshoe bat.” Thus the miners had a coronavirus but it apparently was not SARS itself.
These findings of the thesis are significant in several ways. First, in the light of the current coronavirus pandemic it is evident the miners’ symptoms very closely resemble those of COVID-19 (Huang et al, 2020; Tay et al., 2020; M. Zhou et al., 2020). Anyone presenting with them today would immediately be assumed to have COVID-19. Likewise, many of the treatments given to the miners have become standard for COVID-19 (Tay et al., 2020).
Second, the remote meeting with Zhong Nanshan is significant. It implies that the illnesses of the six miners were of high concern and, second, that a SARS-like coronavirus was considered a likely cause.
Third, the abstract, the conclusions, and the general inferences to be made from the Master’s thesis contradict Zheng-li Shi’s assertion that the miners died from a fungal infection. Fungal infection as a potential primary cause was raised but largely discarded.
Fourth, if a SARS-like coronavirus was the source of their illness the implication is that it could directly infect human cells. This would be unusual for a bat coronavirus (Ge et al., 2013). People do sometimes get ill from bat faeces but the standard explanation is histoplasmosis, a fungal infection and not a virus (McKinsey and McKinsey, 2011; Pan et al., 2013).
Fifth, the sampling by the Shi lab found that bat coronaviruses were unusually abundant in the mine (Ge at al., 2016). Among their findings were two betacoronaviruses, one of which was RaTG13 (then known as BtCoV/4991). In the coronavirus world betacoronaviruses are special in that both SARS and MERS, the most deadly of all coronaviruses, are both betacoronaviruses. Thus they are considered to have special pandemic potential, as the concluding sentence of the Shi lab publication which found RaTG13 implied: “special attention should particularly be paid to these lineages of coronaviruses” (Ge at al., 2016). In fact, the Shi and other labs have for years been predicting that bat betacoronaviruses like RaTG13 would go pandemic; so to find RaTG13 where the miners fell ill was a scenario in perfect alignment with their expectations.
In our previous article we briefly discussed how the pandemic might have been caused either by a virus collection accident, or through viral passaging, or through genetic engineering and a subsequent lab escape. The genetic engineering possibility deserves attention and is extensively assessed in an important preprint (Segreto and Deigin, 2020).
We do not definitively rule out these possibilities. Indeed it now seems that the Shi lab at the WIV did not forget about RaTG13 but were sequencing its genome in 2017 and 2018. However, we believe that the Master’s thesis indicates a much simpler explanation.
We suggest, first, that inside the miners RaTG13 (or a very similar virus) evolved into SARS-CoV-2, an unusually pathogenic coronavirus highly adapted to humans. Second, that the Shi lab used medical samples taken from the miners and sent to them by Kunming University Hospital for their research. It was this human-adapted virus, now known as SARS-CoV-2, that escaped from the WIV in 2019.
We refer to this COVID-19 origin hypothesis as the Mojiang Miners Passage (MMP) hypothesis. Passaging is a standard virological technique for adapting viruses to new species, tissues, or cell types. It is normally done by deliberately infecting a new host species or a new host cell type with a high dose of virus. This initial viral infection would ordinarily die out because the host’s immune system vanquishes the ill-adapted virus. But, in passaging, before it does die out a sample is extracted and transferred to a new identical tissue, where viral infection restarts. Done iteratively, this technique (called “serial passaging” or just “passaging”) intensively selects for viruses adapted to the new host or cell type (Herfst et al., 2012).
At first glance RaTG13 is unlikely to have evolved into SARS-CoV-2 since RaTG13 is approximately 1,200 nucleotides (3.8%) different from SARS-CoV-2. Although RaTG13 is the most closely related virus to SARS-CoV-2, this sequence difference still represents a considerable gap. In a media statement evolutionary virologist Edward Holmes has suggested this gap represents 20-50 years of evolution and others have suggested similar figures.
We agree that ordinary rates of evolution would not allow RaTG13 to evolve into SARS-CoV-2 but we also believe that conditions inside the lungs of the miners were far from ordinary. Five major factors specific to the hospitalised miners favoured a very high rate of evolution inside them.
i) When viruses infect new species they typically undergo a period of very rapid evolution because the selection pressure on the invading pathogen is high. The phenomenon of rapid evolution in new hosts is well attested among corona- and other viruses (Makino et al., 1986; Baric et al., 1997; Dudas and Rambaut 2016; Forni et al., 2017).
ii) Judging by their clinical symptoms such as the CT scans, all the miner’s infections were primarily of the lungs. This localisation likely occurred initially because the miners were exerting themselves and therefore inhaling the disturbed bat guano deeply. As miners, they may already have had damaged lung tissues (patient 3 had suspected pneumoconiosis) and/or particulate matter was present that irritated the tissues and may have facilitated initial viral entry.
In contrast, standard coronavirus infections are confined to the throat and upper respiratory tract. They do not normally reach the lungs (Perlman and Netland, 2009). Lungs are far larger tissues by weight (kilos vs grammes) than the upper respiratory tract. There was therefore likely a much larger quantity of virus inside the miners than would be the case in an ordinary coronavirus infection.
Comparing a typical coronavirus respiratory tract infection with the extent of infected lungs in the miners from a purely mathematical point of view indicates the potential scale of this quantitative difference. The human aerodigestive tract is approximately 20cm in length and 5cm in circumference, i.e. approximately 100 cm2 in surface area. The surface area of a human lung ranges from 260,000-680,000 cm2 (Hasleton, 1972). The amount of potentially infected tissue in an average lung is therefore approximately 4500-fold greater than that available to a normal coronavirus infection. The amount of virus present in the infected miners, sufficient to hospitalise all of them and kill half of them, was thus proportionately very large.
Evolutionary change is in large part a function of the population size. The lungs of the miners, we suggest, supported a very high viral load leading to proportionately rapid viral evolution. Furthermore, according to the Master’s thesis, the immune systems of the miners were compromised and remained so even for those discharged. This weakness on the part of the miners may also have encouraged evolution of the virus.
iii) The length of infection experienced by the miners (especially patients 2, 3 and 4) far exceeded that of an ordinary coronavirus infection. From first becoming too sick to work in the mine, patient 2 survived 57 days until he died. Patient 3 survived 120 days after stopping work. Patient 4 survived 117 days and then was discharged as cured. Each had been exposed in the mine for 14 days prior to the onset of severe symptoms; thus each presumably had nascent infections for some time before calling in sick (See Table 2 of the thesis).
In contrast, in ordinary coronavirus infections the viral infection is cleared within about ten to fourteen days after being acquired (Tay et al., 2020). Thus, unlike most sufferers from coronavirus infection, the hospitalised miners had very long-term bouts of disease characterised by a continuous high load of virus. In the cases of patients 3 and 4 their illnesses lasted over 4 months.
iv) Coronaviruses are well known to recombine at very high rates: 10% of all progeny in a cell can be recombinants (Makino et al., 1986; Banner and Lai, 1991; Dudas and Rambaut, 2016). In normal virus evolution the mutation rate and the selection pressure are the main foci of attention. But in the case of a coronavirus adapting to a new host where many mutations distributed all over the genome are required to fully adapt to the new host, the recombination rate is likely to be highly influential in determining the overall speed of adaptation by the virus population (Baric et al., 1997).
Inside the miners a large tissue was simultaneously infected by a population of poorly-adapted viruses, with each therefore under pressure to adapt. Even if the starting population of virus lacked any diversity, many individual viruses would have acquired mutations independently but only recombination would have allowed these mutations to unite in the same genome. To recombine, viruses must be present in the same cell. In such a situation the particularities of lung tissues become potentially important because the existence of airways (bronchial tubes, etc.) allows partially-adapted viruses from independent viral populations to travel to distal parts of the lung (or even the other lung) and encounter other such partially-adapted viruses and populations. This movement around the lungs would likely have resulted in what amounted to a passaging effect without the need for a researcher to infect new tissues. Indeed, in the Master’s thesis the observation is several times made that areas of the lungs of a specific patient would appear to heal even while other parts of the lungs would become infected.
v) There were also a number of unusual things about the bat coronaviruses in the mine. They were abnormally abundant but also there were many different kinds, often causing co-infections of the bats (Ge et al., 2016). Viral co-infections are often more infectious or more pathogenic (Latham and Wilson, 2007).
As the WIV researchers remarked about the bats in the mine: “we observed a high rate of co-infection with two coronavirus species and interspecies infection with the same coronavirus species within or across bat families. These phenomena may be owing to the diversity and high density of bat populations in the same cave, facilitating coronavirus intra- and interspecies transmissions, which may result in recombination and acceleration of coronavirus evolution.” (Ge et al., 2016).
The diversity of coronaviruses in the mine suggests that the miners were similarly exposed and that their illness may potentially have begun as co-infections.
Combining these observations, we propose that the miners’ lungs offered an unprecedented opportunity for accelerated evolution of a highly bat-adapted coronavirus into a highly human-adapted coronavirus and that decades of ordinary coronavirus evolution could easily have been condensed into months. However, we acknowledge that these conditions were unique. They and their scale have no exact scientific precedent we can refer to and they would be hard to replicate in a lab; thus it is important to emphasize that our proposal is fully consistent with the underlying principles of viral evolution as understood today.
In support of the MMP theory we also know something about the samples taken from the miners. According to the Master’s thesis, samples were taken from patients for “scientific research” and blood samples (at least) were sent to the WIV.
“In the later stage we worked with Dr. Zhong Nan Shan and did some sampling. The patient* tested positive for serum IgM by the WuHan Institute of Virology. It suggested the existence of virus infection” (p62 in the section “Comprehensive Analysis”.) (*The original does not specify the number of patients tested.)
The Master’s thesis also states its regret that no samples for research were taken from patients 1 and 2, implying that samples were taken from all the others.
We further know that, on June 27th, 2012, the doctors performed an unexplained thymectomy on patient 4. The thymus is an immune organ that can potentially be removed without greatly harming the patient and it could have contained large quantities of virus. Beyond this the Master’s thesis is unfortunately unclear on the specifics of what sampling was done, for what purpose, and where each particular sample went.
Given the interests of the Shi lab in zoonotic origins of human disease, once such a sample was sent to them, it would have been obvious and straightforward for them to investigate how a virus from bats had managed to infect these miners. Any viruses recoverable from the miners would likely have been viewed by them as a unique natural experiment in human passaging offering unprecedented and otherwise-impossible-to-obtain insights into how bat coronaviruses can adapt to humans.
The logical course of such research would be to sequence viral RNA extracted directly from unfrozen tissue or blood samples and/or to generate live infectious clones for which it would be useful (if not imperative) to amplify the virus by placing it in human cell culture. Either technique could have led to accidental infection of a lab researcher. Our supposition as to why there was a time lag between sample collection (in 2012/2013) and the COVID-19 outbreak is that the researchers were awaiting BSL-4 lab construction and certification, which was underway in 2013 but delayed until 2018.
We propose that, when frozen samples derived from the miners were eventually opened in the Wuhan lab they were already highly adapted to humans to an extent possibly not anticipated by the researchers. One small mistake or mechanical breakdown could have led directly to the first human infection in late 2019.
Thus one of the miners, most likely patient 3, or patient 4 (whose thymus was removed), was effectively patient zero of the COVID-19 epidemic. In this scenario, COVID-19 is not an engineered virus; but, equally, if it had not been taken to Wuhan and no further molecular research had been performed or planned for it then the virus would have died out from natural causes, rather than escaped to initiate the COVID-19 pandemic. https://www.scoop.co.nz/stories/SC2008/S00025/a-proposed-origin-for-sars-cov-2-and-the-covid-19-pandemic.htm
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