Single-step recovery of mRNA via multimodal chromatography to advance vaccine manufacturing

RNA is an emerging technology in the vaccine field due to its adaptability to new targets, and its flexibility and agnostic manufacturing process. The production process presents high yield at high speed. However, the downstream process is highly dependent on multiple purification steps, which to some extent hinders the flexibility and cost-effectiveness that is required for a manufacturing platform. In this contribution, we explore the use of multimodal chromatography to separate RNA from product and process-related impurities in a single purification step. In particular, we explore the use of Nuvia aPrime 4A, a multimodal resin that combines a strong anion exchanger with a phenyl group, to purify mRNA from in vitro transcription (IVT) samples, without resorting to the use of enzymes or pre-purification steps. By exploring the hydrophobic differences between the mRNA and its impurities, namely nucleotides, DNA template and dsRNA, a binding step was set to increase mRNA binding while flowing impurities. mRNA recovery was maximised by exploring the effect of the pH. This allows to achieve an RNA recovery yield of 81±5 %, with a purity of 88±2 % with no detectable amounts of DNA and a 65 % reduction in dsRNA. Using this simple single-step purification method, a high-quality mRNA product can be obtained without the need for a sequence of purification steps in the mRNA manufacturing platform. In the future, this has the potential to reduce process time, and ultimately lower the cost of RNA manufacturing.