Precisely how does Pfizer's Covid-19 mRNA vaccine work?

[Ygggdrasil]

Is the sequence of the mRNA (including modified nucleotides) in the public domain? Does it code any enzymes in addition to the spike protein?

Here's a good piece describing the components of the vaccine (though, again, the exact sequence of the mRNA appears to be proprietary): https://www.technologyreview.com/20...-the-ingredients-of-pfizers-covid-19-vaccine/

I assume the " trimerised SARS-CoV-2 S glycoprotein RBD antigen " is the spike protein consisting of three protein chains?

Yes. The S glycoprotein is another name for the spike protein (S stands for spike). A glycoprotein is a protein that has sugars attached to it. Most proteins on the surfaces of cells have sugars attached to them, and the spike protein in no exception. The RBD stands for the receptor binding domain, and refers to a specific part of the spike protein that binds to the ACE2 protein on the surface of cells. You want antibodies to target the RBD of the spike protein because these antibodies could interfere with attachment of the virus to cells. On the surface of the viruses, three spike proteins come together to form an active trimer, so timerization of the antigen in the vaccine helps to mimic how the spike protein looks on the outside of viruses.

 

[Ygggdrasil]

Is the sequence of the mRNA (including modified nucleotides) in the public domain? Does it code any enzymes in addition to the spike protein?

Here's a source that apparently has the sequence of the Pfizer mRNA vaccine: