Are Koch’s postulates satisfied?
Some people who are a lot smarter than me (wow….that’s a lot of people) claim that Koch’s postulates were not satisfied when identifying Corona Virus. Here are the rules:
“In 1890, Robert Koch described the basis rules that scientists use to determine if an infectious organism causes a specific disease. These four rules are called “Koch’s postulates.”
The organism must be found in people with the disease and be absent in people without the disease.
The organism must be able to be grown from tissues or other specimens from the affected individual in the laboratory.
The organism must cause the disease when given to an unaffected healthy person.
The organism must again be grown from this second individual.”
Seems to me that these criteria have been satisfied. What am I missing?
The Koch’s postulates are paraphrased here: https://en.wikipedia.org/wiki/Koch’s_postulates
For SARS, research like this exists: “Koch’s postulates fulfilled for SARS virus”, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7095368/ (published in Nature in 2003).
And this: “The aetiology of SARS: Koch’s postulates fulfilled”, https://royalsocietypublishing.org/doi/10.1098/rstb.2004.1489 (published by Royal Society in 2004).
As far as I can tell, this research from 2003 and 2004 is unquestioned. To my knowledge, no equivalent research exists for SARS-CoV-2, maybe except this paper: “The pathogenicity of SARS-CoV-2 in hACE2 transgenic mice”, https://www.nature.com/articles/s41586-020-2312-y (published in Nature, May 2020). This paper is a weak claim, and that’s where the dispute starts.
Is it even a valid challenge to apply Rober Koch’s postulates published and refined between 1884 and 1890 to current science? Some current scientists disagree, e.g. Siouxsie Wiles, https://www.auckland.ac.nz/en/news/2020/11/16/kochs-postulates-covid-and-misinformation-rabbit-holes.html.
If you still want Koch’s postulates to be applied to SARS-CoV-2, the question is if SARS-CoV-2 has ever been properly isolated in the strict sense of Koch’s postulates. Some people have croudfunded a challenge to
[…] present any text passages from publications that scientifically prove the process of isolation of SARS-CoV-2 and its genetic substance. If no publication can be presented, control experiments and the crucial alignment have to be carried out […]
Currently, there are 225.000 Euros (about $272,470 USD) in this ‘Isolate Truth Fund’ as shown here: https://www.samueleckert.net/isolat-truth-fund/
So far, nobody has claimed this awarded almost quarter million Euros, so it seems to be impossible to sctrictly meet the requirements from Koch’s postulates (assuming that 225.000 Euros are a financial incentive for a virologist).
It appears to be similar to Chris’ ‘stick horse’ about the origin of the furin cleavage site. No other Coronavirus has it, how did it get into SARS-CoV-2?
At the end of the day, both questions are academical as they depend on numerous assumptions and constraints. The furin cleavange site coud have naturally mutated into SARS-CoV-2, even if it is not probable. But probable is not the same as impossible. As a scientist, you are free to make a judgement call or an educated guess based on what you believe.
Regarding the isolate, most scientists say that it is technically not possible to fabricate it, but they believe that possible approximations are sufficiently good to make a claim that the isolate could exist. Quoted from memory, virologist Christian Drosten said that a quest for the true isolate would be similarily childish as a hobby pianist criticizing the use of black keys during a performance of a concert pianist.
On the other hand, people like Christian Drosten might not even have filed a proper dissertation (there is an ongoing lawsuit about this) and are still making untenable claims about the applicability of the PCR test for diagnostic puposes (which is the foundation for everything from case numbers to lockdowns). So it boils down to what appears plausible to your own judgement.
Not only we don’t know if the virus was actually isolated, genetic sequencing is not very accurate and takes quite a lot of computer modelling to the most probable sequence, but there’s no guarantee that it’s the actual sequence.