It's mRNA based, if I recall.
This makes it, essentially, endlessly flexible. We can now take a sample, sequence it, find the mutations, simulate what the protein looks like when folded, generate* the correct complimentary protein for that target and write the actual amino acid sequence directly into mRNA and give it to the patient.
This is currently incredibly expensive because it's being done manually by labs full of PhDs. But every part of this process is being rapidly improved and made cheaper.
mRNA based medicines have amazing promise. For example they had the COVID vaccine designed less than 12 hours after sequencing the virus.
*using a diffusion model, like AI image generators but they produce amino acid sequences that generate arbitrarily shaped proteins