mRNA manufacturing quality hinges on in vitro transcription conditions that determine not just how much RNA is made, but whether it is properly capped, tailed and free of immunostimulatory double-stranded RNA byproducts.
yield(t+1) = yield(t) + template*NTPsupply*transcriptionRate - dsRNA_impurity
- Batch grid resolution — how finely different production runs/parameter combinations are sampled.
- Quality target (purity) — the mRNA integrity/purity threshold (capped, poly-A tailed, low dsRNA contaminant) a batch must clear.
- Template/NTP concentration — DNA template and nucleotide triphosphate supply feeding the in vitro transcription reaction.
- Capping efficiency — fraction of transcripts receiving a proper 5' cap, essential for translation and reduced innate-immune activation.
The 2021 mRNA vaccine rollout succeeded partly because manufacturers had already solved exactly this problem at scale: keeping capping efficiency and dsRNA impurity levels tightly controlled across billions of doses.