Is the coronavirus a bioweapon?

There's a conspiracy theory floating around that claims the coronavirus (SARS-CoV-2/COVID-19) was a bioweapon engineered by China.

I don't know how or when it started. Tom Cotton broached the theory back in January:

We still don’t know where coronavirus originated. Could have been a market, a farm, a food processing company.

I would note that Wuhan has China’s only biosafety level-four super laboratory that works with the world’s most deadly pathogens to include, yes, coronavirus. pic.twitter.com/CtuU2czBLp

— Tom Cotton (@SenTomCotton) January 30, 2020

I would add: BSL-4 labs represent the highest level of containment for deadly pathogens. There are only about 50 BSL-4 labs in the world.

My thoughts:

1. Admittedly, I've entertained this theory too.

2. Also, other than those brainwashed by communist Chinese propaganda, no one would be surprised by the possibility that China could have experimented with bioweapons. Certainly the Chinese regime is amoral. Certainly they have the wherewithal to weaponize deadly pathogens.

3. That said, correlation isn't causation. Circumstantial evidence isn't a smoking gun. Just because the coronavirus originated in Wuhan with China's sole BSL-4 lab doesn't necessarily implicate it as a man-made bioweapon.

4. In addition, the coronavirus seems to be quite transmissible, but it's nowhere near (say) the measles.

Also, it seems to have a fatality rate higher than the seasonal flu, but its fatality rate seems quite unlikely to be near as high as the deadliest pathogens.

Plus, though the coronavirus can harm all ages, it primarily affects the elderly, which seems like an odd target for a bioweapon. Why not a more indiscriminate bioweapon that can target any and all? Or at least those of combat age?

In short, if the coronavirus was weaponized, then it seems to be something of a disappointment. It attacks with more of a whimper than a bang.

(Of course, we're still in the midst of the pandemic so it's hard to tell. Anything is possible. But I can only speak from what we know today.)

5. If a mad scientist wishes to create a bioweapon, then my understanding is it's better to take a template from a deadly disease and alter it to make it worse than to try to make a novel pathogen. Ebola, anthrax, smallpox, and/or the plague (Y. pestis) have all been choice candidates to be weaponized precisely because they're already deadly.

Granted, SARS-1 was fairly deadly, and our coronavirus is SARS-2, but at least according to this list SARs-1 isn't even in the top 25 of diseases with the highest fatality rates. In fact, if we wish to stay in the coronavirus family of viruses, then MERS had a higher case fatality rate.

6. At best, the coronavirus could have been a failed attempt to make a deadly bioweapon. Perhaps a bioweapon that was accidentally released before it was "ready". That seems more plausible to me than the successful bioweapon theory, but it still seems implausible overall.

Related, the coronavirus could have been a novel virus that the Chinese had discovered and extracted from an animal (e.g. bats), held under containment in their BSL-4 lab, but the virus inadvertently "escaped" through some error. That seems more plausible to me than either the failed or successful bioweapon theories.

7. More to the point, as most people know, scientists can look at a person's DNA to identify paternity as well as various criminals (e.g. murderers, rapists). Similarly scientists can look at the genetic material of viruses to identify its likely origins. And the fact is many scientists have already performed genomic analyses on the coronavirus. Here are the results:

It is improbable that SARS-CoV-2 emerged through laboratory manipulation of a related SARS-CoV-like coronavirus. As noted above, the RBD of SARS-CoV-2 is optimized for binding to human ACE2 with an efficient solution different from those previously predicted^{7, 11}. Furthermore, if genetic manipulation had been performed, one of the several reverse-genetic systems available for betacoronaviruses would probably have been used¹⁹. However, the genetic data irrefutably show that SARS-CoV-2 is not derived from any previously used virus backbone²⁰. (Source)

8. By contrast, again looking at the coronavirus' genome, there is are very compelling alternative theories for its origin:

Of course, scientists tell us that SARS-CoV-2 did not escape from a jar: RNA sequences closely resemble those of viruses that silently circulate in bats, and epidemiologic information implicates a bat-origin virus infecting unidentified animal species sold in China’s live-animal markets. (Source)

Instead, we propose two scenarios that can plausibly explain the origin of SARS-CoV-2: (i) natural selection in an animal host before zoonotic transfer; and (ii) natural selection in humans following zoonotic transfer. We also discuss whether selection during passage could have given rise to SARS-CoV-2. (Source)

Full-length genome sequences were obtained from five patients at an early stage of the outbreak. The sequences are almost identical and share 79.6% sequence identity to SARS-CoV. Furthermore, we show that 2019-nCoV is 96% identical at the whole-genome level to a bat coronavirus. (Source)

Complete genomes were submitted to GISAID. Phylogenetic analysis revealed that 2019-nCoV falls into the genus betacoronavirus, which includes coronaviruses (SARS-CoV, bat SARS-like CoV, and others) discovered in humans, bats, and other wild animals.¹⁵ (Source)

Last, while phylogenetic analysis indicates a bat origin of 2019-nCoV, 2019-nCoV also potentially recognizes ACE2 from a diversity of animal species (except mice and rats), implicating these animal species as possible intermediate hosts or animal models for 2019-nCoV infections. (Source)

From these results, the new 2019‐nCoV is distinct from SARS virus, probably trasmitted from bats after mutation conferring ability to infect humans. (Source)

The levels of genetic similarity between the 2019-nCoV and RaTG13 suggest that the latter does not provide the exact variant that caused the outbreak in humans, but the hypothesis that 2019-nCoV has originated from bats is very likely. (Source)

Five of these six residues are mutated in SARS-CoV-2 compared to its most closely related virus, RaTG13 sampled from a Rhinolophus affinis bat, to which it is ~96% identical²...As many of the early cases of COVID-19 were linked to the Huanan seafood and wildlife market in Wuhan, it is possible that an animal source was present at this location. Given the similarity of SARS-CoV-2 to bat SARS-like CoVs, particularly RaTG13, it is plausible that bats serve as reservoir hosts for SARS-CoV-2. It is important, however, to note that previous outbreaks of betacoronaviruses in humans involved direct exposure to animals other than bats, including civets (SARS) and camels (MERS), that carry viruses that are genetically very similar to SARS-CoV-1 or MERS-CoV, respectively. By analogy, viruses closely related to SARS-Cov-2 may be circulating in one or more animal species. (Source)

The SARS-CoV-2 virus is a betacoronavirus, like MERS-CoV and SARS-CoV. All three of these viruses have their origins in bats. (Source)