Paper examines literature around gain-of-function and zoonotic origin, says there is not enough evidence to decide whether #SARS-CoV-2 ( the #coronavirus that causes #COVID-19 ) became infectious to humans through either method.
> The virus that caused the pandemic is known officially as SARS-CoV-2, but can be called SARS2 for short. As many people know, there are two main theories about its origin. One is that it jumped naturally from wildlife to people. The other is that the virus was under study in a lab, from which it escaped. It matters a great deal which is the case if we hope to prevent a second such occurrence.
> I’ll describe the two theories, explain why each is plausible, and then ask which provides the better explanation of the available facts. It’s important to note that so far there is no direct evidence for either theory. Each depends on a set of reasonable conjectures but so far lacks proof. So I have only clues, not conclusions, to offer. But those clues point in a specific direction. And having inferred that direction, I’m going to delineate some of the strands in this tangled skein of disaster.
@geniusmusing One thing I have come across a couple of times is that the vaccines are not expected to completely prevent infections, but instead to reduce the severity thereof. Thus, you may become infected (and maybe even pass the #SARS-CoV-2 #coronavirus to others) despite having taken your shots.
I recently skipped a friend’s wedding reception despite being vaccinated. The reason was because there were some required tasks at work that day, but afterward, I learned that people were maskless and close together (and I only knew a few of the people). I would have been even more uncomfortable than I already am in those situations.
I admit that it does bother me a little when experts are very sure of something that they have no way of knowing. It is okay to say that we do not really know where #SARS-CoV-2 came from and thus do not know how the #COVID-19 outbreak started.
@vegosf05 I like the fact that the author does not say that #SARS-CoV-2 definitely came from either wildlife-to-human or laboratory-escape scenarios. Though it is clear which direction he leans, he plainly says there is no actual evidence of either one ... and that he thinks WTH origins should have left some evidence that is currently missing.
Both #Pfizer #BioNTech and #Moderna vaccines are still highly effective after six months, but may require annual boosters to cope with #SARS-CoV-2 variants.
"Receptor recognition is an important determinant of hCoVs infection and pathogenesis. The specific surface protein that provides the entry door in human cells for both SARS-CoV and SARS-CoV-2 is angiotensin-converting enzyme 2 (ACE2) [17–19]. The first difference between the two SARS-CoVs is that SARS-CoV-2 receptor-binding domain (RBD) has a higher ACE2-binding affinity, a characteristic which could lead to a more efficient cell entry [19]. However, ACE2-binding affinity of the entire SARS-CoV-2 S protein seems to be comparable to or even lower than that of SARS-CoV entire S protein."
... .
"Conflicting reports on SARS-CoV-2 pathogenicity may also be related to genetic differences in the expression of the SARS-CoV-2 host cell entry factors among individuals and between populations [26, 27]."