Just to clarify I was talking about the Pfizer and Moderna mRNA vaccines.

AstraZeneca’s vaccine uses adenovirus-vectored technology, which is different [1].

[1] https://www.prevention.com/health/a35118263/astrazeneca-vs-p...

I was aware of that.

From what I read, the mRNA vaccines manages to get the spike in to the cytoplasm, just like the real virus, so it to that extent mimics what is desired.

Whereas the viral vector (a different delivery technology) used for the AZ vaccine manages to get the spike in to the nucleus, due to picking the "wrong" vector, so to that extents it could be said not to mimic what is desired.

There was speculation that if it had used a different vector which delivered to the cytoplasm, then some of the low probability issues may have been avoided. So one could argue that the choice of vector was/is a bug with the AZ vaccine. Despite that, it does seem to be having the desired effect - reduced hospitalisations.

Mind, I've had the AZ vaccine, and so far have survived.

:-)

mRNA vaccines deliver mRNA to the target cell, via merging a lipid bubble into the cell membrane and dumping the contents into the cytoplasm. The mRNA is then translated into a specially designed variant of the spike protein that is embedded facing out of the cell membrane. As it happens, the physical details of embedded protein translation means that the spike proteins never see the cytoplasm at all, being restricted to the endoplasmic reticulum.

Thanks.

That is what I read, just that I couldn't remember the term "endoplasmic reticulum", and so used "cytoplasm" as a hand wavy stand in.

:-)