Thread by @Ayjchan

Before the WHO-convened global study on the #OriginsofCovid releases their interim report this week (maybe), I think it's useful to explain to the public where all the evidence lies right now across the 4 hypotheses presented by the origins team
who.int/publications/m…

For the sake of simplicity, hypotheses 1 and 2 can be combined into scenario A, which includes virus transmission from the animal reservoir (most likely bats) directly into humans or through an intermediary animal host that is more closely related to humans.

The WHO-convened team stated that cold chain supply (scenario F) is an #originsofcovid hypothesis deserving of follow-up.
Importantly @Peterfoodsafety later clarified they are only considering within-China cold chain food trade, not from outside China.

https://twitter.com/Ayjchan/status/1362471820541231105

Lab origins can be divided into several distinct scenarios requiring different methods of detection & investigation.

Scenarios B, C, and even D likely do not produce a virus with detectable signs of lab manipulation. In other words, viruses emerging B/C/D can look 100% natural.

Sometimes even major engineering (scenario E) can slip pass detection of lab manipulation. The current approaches can only find what they're looking for. If you don't know what's in your opponent's tool kit, you very likely can't detect their signatures.

forbes.com/sites/erictegl…

Viruses escaping from labs can span a wide range of fitness and host preference. They could be well adapted for binding and using receptors in human and other lab animals (scenarios B, C, and D), especially if sampled from localized human outbreaks in isolated rural areas...

... or they could be "fresh" from nature (scenario B).

imo scenarios A and B need to be separated even though both involve animal-to-human transmission outside of a lab, because the route of investigation and the prevention responses are entirely distinct.

The investigation of scenario A is driving hundreds of research personnel or hired hands to sample tens of thousands of wild animals (including bats) and search for localized outbreaks in humans- this is essentially the set up of scenario B, which could risk pathogen emergence.

So where does all the existing evidence sit?

The table is self-explanatory. In summary, there are precedents for both natural & lab-related outbreaks of SARS. No direct evidence reported for any of the hypotheses. Location suggests a lab origin due to distance from SARS spillover zone and proximity of a major SARS lab.

If there are going to be likelihood estimates - at this stage where so much is still unknown - in the WHO-convened #originsofcovid team's report, these estimates should ideally be supported by a substantial analysis of primary (non-aggregated) data relating to each scenario.

I understand that there are likely many interfaces in Wuhan where humans are exposed to live animals, some transported from far away in China. But what are the @WHO team's estimates of the exposure to research-based collection and study of pathogens?

https://twitter.com/Ayjchan/status/1361450090720858120

It's difficult to guess how likely lab origins is considering we don't know how many trips from Wuhan were made (and where) to collect pathogens from animals or humans (scenario B), and how many SARS viruses were collected, sequenced, produced, otherwise studied (scenarios C-E).

We know about cases of mysterious pneumonia, described to be SARS-like, among miners in Mojiang, Yunnan, China in 2012. Important pathogen labs in China, including WIV, followed up & found SARS2-like viruses over the years, but how many other under-reported outbreaks were there?

Unfortunately, several countries do not follow the International Health Regulations (IHR).

Even in the case of the COVID-19 pandemic itself, the World Health Assembly has directed the WHO to evaluate whether IHR were adhered to.

who.int/teams/ihr/ihr-…

I hope that it isn't controversial that, in order to estimate the likelihood of lab origins, it is necessary to first get the actual numbers, as much as is possible, describing the extent of sampling from wildlife and humans suspected to carry pathogens over the past decade.

When the interim report does get published, I hope that this table can be useful to anyone trying to understand whether the WHO-convened team was able to access the data/evidence required to inform likelihood estimates for each #OriginsofCOVID hypothesis.

https://twitter.com/Ayjchan/status/1363527530821660674

If any expert uses language like "a ton of evidence" "overwhelming evidence" "scientific consensus" points to X hypothesis, whether natural spillover, lab origins or #PopsicleOrigins please challenge them on the exact type of evidence they're talking about. Is it just precedents?

Or is it their gut feeling, based on past experience, that there should be a ton of evidence pointing at their hypothesis of choice?

One strange argument I’ve seen is “SARS2 could’ve emerged naturally so that = evidence against/inconsistent with lab origins.”

I don’t think this is logical. That’s like saying a person could’ve driven to point X via route A so that = evidence inconsistent with route B.

In the absence of any direct evidence, the plausibility of one origin doesn’t shoot down the plausibility of other origins. For example, if cold chain origins are shown to be plausible, that doesn’t mean that specific evidence is against or inconsistent with non-frozen origins.

Because the investigation into #OriginsofCOVID is necessarily forensic in nature, any newly revealed intelligence or piece of direct evidence can dramatically change the likelihoods of each of the 4 hypotheses considered by the WHO-convened team.

And I believe that some intelligence already exists, although still classified, which circumstantially point towards lab origins.

Again, just because some evidence may suggest lab origins, does not = against or inconsistent with natural origins.

https://twitter.com/Ayjchan/status/1362085337858773001

More on the previous @StateDept Facts Sheet and the intelligence on the #originsofcovid Start watching at 14:18 min mark.
cbsnews.com/video/former-d…

fyi I have not seen any of this intelligence but the former deputy national security adviser says... cbsnews.com/news/transcrip…