In light of current evidence,
to what extent do you agree with the statement
'SARS-CoV-2 both originated and spread to humans entirely naturally,
i.e. it was neither engineered nor, even if not engineered, did it leak out of a research laboratory'?

The virus most likely initially spread naturally between humans, as it is now. The very start of the spread, however, is unclear. We do not have overwhelming evidence how the initial zoonosis happened -- was it in nature or in a lab, nor how that start occurred. Thus, it is possible that a lab worker was 'naturally' infected in the lab, and then spread it to the outside, just as it is possible that someone caught the virus out in nature.

The big international coronavirus meeting was last week. Nobody in the field mentioned or acknowledged these goofball conspiracies, even in passing. It kind of highlighted that the conspiracies are ideas that only have currency among people who don't really know what they are doing.

engineered and not engineered are very different scenarios; they should have ben separated in this question.

Your statement does not do justice to the complexity around this issue. Of course, the 'origin' of all coronaviruses originated in bats because bat is the reservoir of all coronaviruses. We still do not know whether there was an intermediate host for the 2003 SARS CoV . Took us almost 3 years before we published our JVI paper demonstrating the the Civet cat was the the intermediate host! We have no idea whether there was an intermediate host for the SARS CoV ll/COVID-19. My view, the SARS CoV ll mostly likely was in the freezer in WIV and spread around the world starting Dec 2019!

most parsimonious explanation and most likely scenario - still

My vote 'mostly' from the early year remains unchaged. It seems that the pandemics was elicited by series of natural unlucky events: (i) More and more scientific data point to the fact that in the beginning there was a recombination event between a bat and pangolin virus which gave rise to the SARS-CoV-2 progenitor. (ii) Following of a zoonotic transfer to human the progenitor virus acquired mutations changing its structural proteins some of which apparetly lead to increased transmissivity. Such a proces could have been unnoticed in a small cohort of people for relatively long time (definitely before 2019). (iii) The third 'bad luck' was induced by a purely anthropomorphic factor, namely our globalised civilisation which allowed rapid spreading of the virus worldwide.

Nothing has changed sine my last vote

No current evidence to suggest something other than natural zoonosis although more transparency would be very useful including access to all the sequence data generated in WIV for a year prior to November 2019

It depends how you consider the term 'natural'. I would expect a farmed (wildlife) animal may be involved in proximate transmission to humans and this is 'natural' transmission or zoonosis as defined by WHO but this cannot be described to be from nature. I expect the original virus did come from bats but maybe not 'naturally' and this is where the lab leak is plausible with viruses being collected over years - a mistake and spill over in the lab is a possibility. I doubt gain of function research was used cryptically but this might effectively have 'happened' e.g. in a mink or civet farm with virus spilling from cage to cage and then to a handler. Direct spill over is also possible from a wild species such as a bat but we have no evidence yet to confirm this and the virus may have changed substantially and we will never know....

the lack of transparency from the Chinese government and the reactions to the request to investigate the outbreak more in depth do not convince me yet

The recent paper in Cell (https://doi.org/10.1016/j.cell.2021.06.008) has reported many new coronaviruses discovered in bats including several strains are closer to SARS-CoV-2 than the one that reported by WIV in 2020. The finding in this cell paper could reject the lab-leak hypothesis which assumed the strain reported by WIV was the ancestor of SARS-CoV2. There are increasing evidences supports that the more we dig out in the nature, we will be closer to the true.

I am increasingly convinced that the virus emerged from the wild, from bats.

With other pandemic/epidemic human coronaviruses (SARS, MERS) and also historical endemic human coronaviruses there is precedent based on genetic analysis for interspecies transmission from bat host reservoirs to intermediate hosts and spillover to humans. The closest strains to SARS-CoV-2 genetically are from bats, including a recent strain identified from bats in Thailand. SARS-related strains have been confirmed in bats including ones that can bind to the human ACE2 receptor. So there is evidence and precedent for bats as coronavirus reservoir hosts and spillover to humans and also livestock.

More data are accumulating from various countries that COVID-19 existed even before December 2019 when the fist OVID-19 case was reported in China. Those countries include Italy, Spain, and the US, eliminating the possibility that the virus was leaked out from the laboratory. Also, it is highly unlikely SARS-CoV-2 can be engineered, although the engineering technology is available.

what prevented me from ticking 'fully' is the claims that this virus is so much more dangerous than other Corona viruses in so many respects (infectiveness, mortality, short immunity following an infection). This is the only scientific argument, in my view, which justifies discussing the engineered origin.

The spread of the disease seems to be consistent with zoonotic transmission.

There is only the very very very very small chance this could have been engineered/leaked.

SARS-CoV-2 mishandling from a BSL4 Wuhan lab facility is likely to occur. There is no evidence for the engineering of the virus for the sake of pursuing a pandemic. An in depth transparent investigation in lab by independent experts (other than WHO or Chinese government) is therefore warranted in line with an opinion of other researchers.

1- The location of the pandemy start should be highly unlikely to be downtown Wuhan when these type of viruses are naturally found >1000 miles away. 2- The sequence of the Spike protein is highly unlikely to have evolved naturally, in particular with i) the Furin-Cleavage Site which is unique to SARS-CoV2 in sarbecoviruses, ii) has 2 rare codons in a row that are very seldom used in Coronaviruses, iii) is higly biased in the third base of the codon ONLY in a defined place of the Spike 3- The PI of the Zhou et al. Nature paper (Zhengli Shi) stated in an interview in Science that 'she was relieved when she checked that there was no such sequence in her lab', and she later admitted that there was the 4991 isolate sequence which is 100 % homologous--She thus lied. 4- She admitted also that 8 other SARS sequences were found in the TG cave. Why are the sequences not available? 5- The thesis describing the physiopathology clearly says that it is a SARS-like disease, and that samples were taken to Wuhan, which in itself is a strong reason tobelieve that it is a probable source of emergence. 6- The PI of the Zhou et al. Nature paper (Zhengli Shi) ommitted to show in the Extended data Figure 3 the insertion at aa position 680 of this totally novel Furin Cleavage Site. Since she has been working n these sites in the past, it is totally unlikely that she (and 28 other to chinese virologist authors) did not see it. They stopped the aa alignement at aa 685.They chose or were told not to mention it, indicating that it was troublesome. 7- the evidence of a natural origin is not supported by any serious claim other than the wishful thinking 'it evolved from a natural host'. The intermediate host is still missing. 8- there are serious problems with the assembly and veracity of the RaTG13 sequence. 9- If it is evolved naturally why China is blocking the WHO team? 10- If it is evolved naturally why China is blocking access to sequence databases since october 2019?

It is the breakdown of barriers between humans and animals (habitat loss, wet markets, intensive farmign systems) that are promoting emergence of zoonotic diseases. Not engineered diseases, but the causativew factors are human pressures.

The zoonotic origin of the current SARS-CoV-2 virus is the most likely option, and it is what often happens in the contest of interaction of human with animals. There is no reason, at the moment, to think differently.

Based on the phylogenetic analyses of the circulating strains there is no evidence that this virus came from a laboratory

A virus scape from a BSL4 facility is likely to occur, though not necessarily was engineered pursuing a pandemic

As long as there is no evidence to suggest otherwise, the default must be that this is a zoonotic virus whose host jump occurred naturally

If it is evolved naturally why China is blocking the WHO team.

There are genetically diverse SARS-related coronaviruses which exist in their natural reservoirs for a long time. SARS-CoV and SARS-CoV-2 are two examples jumping to humans.