mRNA technology does not use cultured cell lines of any kind, human or animal. This is one of the aspects that make it a technological leap forward. They are basically designed and synthesized in the lab rather than cultured in petri dishes. This saves a lot of time both in development and manufacturing.
More importantly it opens the door to designer vaccines for cancer treatment. Identify cancer specific proteins and design ab mRNA vaccine to teach the immune system to destroy it.
It also means they may finally have flu shots that work and can be made in weeks when the strain is actually known, rather than guessing a year in advance in order to have time to culture it.
My doc (MD and Epidemiology degreed) told me what you said last week
But..I also told him I wanted to wait a year...he’s already had both vaxes