For a typical recombinant subunit vaccine, you'd need to splice any new changes into whatever's churning out your proteins (bacteria, yeast, etc.) and then go g

For a typical recombinant subunit vaccine, you'd need to splice any new changes into whatever's churning out your proteins (bacteria, yeast, etc.) and then go get those proteins after growing them -- assuming all goes well. For an mRNA vaccine, you can skip the entire protein translation and production step.