GMP production is overall a more costly process. This has many reasons. The raw products used during GMP manufacturing are of higher purity, which comes at higher price tags. Dedicated production areas are required (e.g. cleanrooms). Validation is needed for cleaning methods and the final GMP product is of high purity, which has been confirmed via an array of validated analytical methods.
The short supply is due to the substantial growth of the global cell and gene therapy market in addition to vaccines and cancer treatment applications. In the last two years a big increase has been reported in the number of investigational new drugs and multiple drugs are being licensed for commercial distribution. Due to this increase, contract manufactures which provide GMP-grade plasmids are struggling to keep up with the increasing demand. The recent pandemic has exacerbated the problem, as a lot of vaccine candidates are being developed, including DNA-based vaccines and mRNA-based vaccine where the plasmid DNA is required as starting material for the in vitro transcription process of mRNA.