Vincent Racaniello, a leading virologist (https://www.microbe.tv/twiv/) seems to think that the genetic sequence of the covid virus and the bat version of the virus are nearly identical. That genetic evidence seems to suggest that the covid virus had a natural bat source.
Vincent talks about and shows safety practices for a "level 4 biolab" (https://www.bu.edu/articles/2013/video-offers-glimpse-of-bio...)
It might be the case that the biolab safety protocols were not followed. This seems unlikely.
It might be the case that there was a cross-species transfer of the virus. This is a frequent event between species.
Scientifically, a lab leak is less likely than a species-transfer. Politically, a lab leak is the only possible (i.e. politically useful) explanation.
So your sources of information comes from a world-leading virologist and a state department spokesperson.
You decide.
The WIV handled those novel viruses at BSL-2, not BSL-4. Dr. Shi acknowledged this explicitly in her interview with Science, linked below. Even Ralph Baric (who originated many of the techniques that the WIV scaled up, and whose own research was controversial long before the pandemic) has said that was an unacceptable risk.
https://web.archive.org/web/20210727042832/https://www.scien...
If SARS-CoV-2 arose from a research accident, then it was probably from an American-funded Chinese lab, using techniques developed primarily by an American. So I don't see the political benefit to either country in entertaining that possibility, though I do see a benefit to both countries to downplaying it (as seems to have occurred).
Long before the pandemic, a small subset of virologists and adjacent scientists advocated strongly for certain high-risk research on potential human pandemic pathogens, including laboratory enhancement of existing viruses (gain of function) and hunting of novel viruses from nature. That work was highly controversial, to the point that a three-year moratorium on funding was imposed, ending in 2017. Racaniello was among those advocates; so while he's certainly better-informed than the average person, he also faces a massive conflict of interest. I don't see why you'd trust him over the countless well-credentialed scientists who consider the origin of SARS-CoV-2 to be an open question.
re: BSL-2 vs BSL-4 ... Assuming it WAS a lab leak, was there an a-priori reason to believe that among the many different naturally occurring viruses under study that SARS-CoV-2 would cause a worldwide pandemic? Bats are known to have hundreds of different viruses. Ebola and HIV seem to have been spread widely without a lab connection.
As for gain-of-function studies, they might be beneficial. One might, for example, modify a DNA-modifying virus to add a gene for expressing insulin, providing a cure for diabetes. A DNA-modifying virus provides an ideal whole-body carrier for genetic disorder correction. Indeed this hackernews post (https://news.ycombinator.com/item?id=40307138) today shows a deaf girl cured through genetic manipulation. See https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4786910/
Nobody important, just a congressional subcommittee tasked with investigating the pandemic. That's all.
I'm not commenting on the veracity of it or not... just making sure to call out that a tweet of a letter is not the same thing as the documents themselves. The letter even says as much - that we need the content to be opened to the public.
With the massive misinformation campaigns that are ongoing in our world, is important to be sure people dig all the way down to facts, and don't just accept tweets at face value.
Conspiracy: In criminal law, a conspiracy is an agreement between two or more people to commit a crime at some time in the future. Criminal law in some countries or for some conspiracies may require that at least one overt act be undertaken in furtherance of that agreement, to constitute an offense.
So, a tested hypothesis supported by evidence of an agreement between two or more people to commit a crime.
And the english-speaking public has been brainwashed into thinking these words mean something completely different when combined.
SARS-CoV-2 is a novel sarbecovirus, differing from SARS-1 in the spike by about 20%, with an FCS. The WIV proposed in DEFUSE to study viruses with exactly those properties, by collection from nature followed by laboratory manipulation. That proposal wasn't funded, but leaked documents claim the work proceeded with other funders. No other site anywhere in the world has been known to conduct or propose such research; refutations like "lots of big cities have virology labs" miss the uniqueness. Dr. Shi herself did not expect natural spillover in Wuhan, far from the caves established (mostly by her team) to carry the greatest diversity of similar viruses.
None of the biological therapeutics that you mention are scientifically controversial. (Some aspects e.g. of flu vaccine manufacturing get closer to the edge, but not too close.) The concern is the deliberate search--whether in remote areas of nature, or by laboratory manipulation--for deadlier and faster-spreading human pathogens, which are deliberately just one containment failure away from a novel pandemic. It's unfortunate that the unqualified phrase "gain of function" has become publicly associated with such work, since many harmless or beneficial genetic changes can also be described as a "gain of function". The professional term of art is "enhanced potential pandemic pathogens" (ePPP), which is much clearer.
Whatever the name, no such research has ever delivered any public benefit. Its supporters are a tiny subset of virologists, but a particularly vocal subset given what's at stake for them (funding, reputation, etc.) personally. I hope you won't listen only to them, and I particularly hope you won't let them conflate their narrow domain with the whole of modern virology. They're hoping to cloak their risky and speculative experiments in the benefits provided by the rest of the field; but I'm afraid they're more likely to induce a political overreaction in which lifesaving research is banned.