A quick update on a COVID-19 origins-related discovery making headlines this week — and often for the wrong reasons.
The Telegraph is reporting the finding of a “new COVID virus” in Brazil. That headline is inaccurate: COVID-19 is a disease caused only by SARS-CoV-2. The new virus, BRZ batCoV, is something different — and its discovery actually reinforces what scientists already know about: That nature, not engineers, created the Furin cleavage site in SARS-CoV-2.
Here is the quick rundown of the discovery:
An international team of scientists has discovered a new coronavirus, BRZ batCoV, in moustached bats from Brazil that carries a furin cleavage site — a key genetic feature also found in SARS-CoV-2. While the Brazilian bat virus is quite divergent from an overall sequence perspective, forming probably its own subgenus next to the Sarbeco- and Merbecoviruses, its amino acid sequence and position at the critical S1/S2 junction, forms a functional cleavage site remarkably reminiscent to the one observed in SARS-CoV-2.
Of note, the spike protein of this novel bat coronavirus possesses a functional furin cleavage site at the S1/S2 junction with a unique amino acid sequence motif (RDAR) that differs from that found in SARS-CoV-2 (RRAR) by only one amino acid. - Takada K. et al., bioRxiv, 2025
This finding is significant, but not surprising.
As I wrote previously, these cleavage sites are not unique by any means; in fact, they independently develop all the time in the wider coronavirus family. The wider CoV family tree is sprinkled with FCS sites at the S1/S2 position.
This is not surprising either, because FCS are very short sequences (4 amino acids) and these polybasic cleavage motifs will happen over and over just by chance through recombinations, insertions, or mutations. Most FCS motifs are likely acquired de novo and just don’t stick around if selection pressures do not favor them.
Furthermore, there is good evidence that the S1/S2 boundary region of the genome is a highly variable region in all CoVs and more permissive to genetic alterations than the wider genome through point mutations, insertion, and recombination mechanisms.
The authors find this as well by investigating the protein structure in the S1/S2 region of the BRZ batCoV
"…our results suggest that FCS acquisition is impacted by protein-level constraints, with the S1/S2 junction representing a structurally permissive “hotspot” for stable incorporation of cleavage motifs. - Takada K. et al., bioRxiv, 2025
Again, this just adds to the picture we already had. To support this notion of a ‘higher dynamic’ at the S1/S2 location, another genomic study of SARSr-CoVs in European bats found some indications that FCS at this location might pop in and out of existence in Sarbecoviruses at very low frequencies in a population.
Overall, this discovery adds to our already exisiting evidence basis that nature is perfectly capable of creating a furin cleavage site, no engineer needed.
The Brazilian bat virus kindly cements that point right on the nose by containing a very similar looking FCS
And if you need any more convincing that the FCS we observe in SARS-CoV-2 is natural and was not engineered, I’ve written a very long article about it, but just look at that hot mess below:
Alright, so science does what science does, continuously adding new nuggets of evidence to an already existing body of knowledge.
The day closes with another L for the lab leakers, as is typical when it comes to scientific support for their fantasy.
Anyways, what else is new?
Rand Paul keeps digging a rabbit hole to hide in:
Sometimes, it is hard to convey how ignorant, dishonest and malicious political actors have been on this topic.
Rand Paul treats virology papers the way flat-earthers treat NASA photos: highlights the wrong part, zooms in 400%, and calls it a smoking gun.
That will not change anytime soon, but for anybody who wants to understand why this fabricated origin controversy has reached the highest halls of power, you know I got you covered:
Lab Leak Fever
Outbreaks of new diseases are almost always shrouded in mystery. But rarely does an unanswered scientific question reach the peak of the attention economy and influence world matters. Suspicions about a research-related accident have since put the work and life of scientists involved in the search for the origin of COVID under pressure. There is a sayin…
Alright, that is it for my origins news dispatch.
Stay safe, stay smart, stay connected.
Need to spell out RDAR next time. Unless your target audience are PHDs or at a minimum biological science majors. Otherwise liked the read. Good information that unfortunately will not get picked up in large media platforms.