For instance, South Africa has previously observed similar huge evolutionary jumps in single immunosuppressed patients with HIV. A similar case was observed in Europe with leukaemia.
The case distribution and timing makes it extremely likely that it emerged in the region, yes.
Given the evidence, the only reason for claiming that vaccine selective pressure is the only or even most likely explanation is a statement driven by ideology not reality.
I don't really think so. We can safely say we are exploring where the latest originated and comparison of hypotheses overall likelihood is difficult to do in even simple cases and huge data in a well defined regime like physics. Our back of the napkin handwaves are piss in the wind.
> The case distribution and timing makes it extremely likely that it emerged in the region, yes.
It emerged in a population but originated in a particular body, it makes it almost pointless to say it came from this or that country when we are trying to understand the actual body it came from. (I say body because there is another thread discussing mouse origins).
> Given the evidence, the only reason for claiming that vaccine selective pressure is the only or even most likely explanation is a statement driven by ideology not reality.
Totally. I think someone is exploring one of their pet theory and how it fits with this evidence.
Perhaps, but it's my understanding that Omicron was first observed in diplomats that had already received multiple vaccinations. See: https://www.nytimes.com/2021/12/03/world/botswana-diplomats-...
One hypothesis involves the fact that current mRNA vaccines induce an immune response highly targeted toward the spike protein RBD.
In contrast, natural infection induces a broader immune response that includes antibodies targeting other proteins (Nucleocapsid protein being one of the most notable; it is commonly used to determine if a prior infection occurred).
Omicron in particular is a variant that has accumulated a significant number of mutations in the S protein region.
Is this coincidence or are we seeing selective pressure due to mass vaccination campaigns?