Regarding the mRNA COVID vaccines I get the impression as a non-expert that forcing humans cells to produce a non-human protein with non-human/"foreign" genetic code sounds highly unethical & dangerous in terms of unknown effects from doing this.

Most of the concerns that I hear about regarding these vaccines seem to be primarily focused on the spike protein that's produced from vaccination, but I don't see much discussion regarding the ethics of forcing the human body/cells to produce non-human proteins (aside from the idea that the mRNA could somehow change human DNA).

Are there any instances of human cells taking in non-human genetic code & producing non-human proteins (like the vaccine) "in nature" that somehow suggest that mRNA vaccine technology is ethical?

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