mRNA vaccines are precise, safe, and flexible – and the growing interest in their potential to respond rapidly to pandemic outbreaks highlights the need for facilities that can scale up to meet demand. This involves a complex manufacturing process that requires significant quantities of highly purified ingredients. These ingredients often require storage and handling in hazardous areas, necessitating a bespoke facility design that can support the specific process needs of individual projects.

mRNA Production

As mRNA-encoded immunogens are proven to be efficacious for treating severe serious diseases, the industry is working toward rapid mRNA manufacturing to support vaccine production in a public health emergency. This area is of intense interest as the vaccines can be produced in just weeks from the availability of a sequence encoding the desired immunogen, and the process is cell-free. Messenger RNA (mRNA) is an ingenious natural molecule that allows cells to translate genetic information into proteins. This process forms the basis of a new breed of vaccines developed rapidly in response to the COVID-19 pandemic. It can address unmet needs in medicine across a range of pathologies. Unlike cell-culture-based vaccines, mRNA production does not require animal raw materials, making it safer than conventional vaccine manufacturing processes.

Nevertheless, the mRNA production process requires intricate steps and procedures under strict quality control. Moreover, the production of mRNA is a highly flammable process and, therefore, requires several tailored containment, handling, and storage measures. This necessitates that facilities designed to produce mRNA vaccines comply with higher hazardous area categories and may be restricted in their capacity to operate during non-pandemic times.

Sterilization

mRNA contains instructions for making viral proteins, the part of the virus that causes disease. Once delivered into a cell, the mRNA is translated into corresponding proteins, which are recognized as foreign and provoke a robust immune response. Scientists must first generate mRNA at a laboratory scale under current good manufacturing practice (cGMP) to produce mRNA for clinical use. Although commercial kits exist to perform this reaction, their quality is compromised by the need to purchase specialized cGMP-grade materials, such as 5’ cap analogs and modified UTPs, which can add significantly to the cost per dose of the vaccine.

Sterilization eliminates all microbiological life (vegetative and spore forms) using various physical and chemical methods. A standard method is UV radiation, which kills bacteria and other spores by destroying their DNA or RNA molecules, thus rendering them ineffective. Moving the mRNA production process to continuous processing can reduce costs by up to a factor of five and increase productivity by 20%. This is due to reduced personnel and consumable expenditures and lower batch failure rates.

Filtration

In a filtration process, insoluble solids are removed from liquid or gaseous fluids by passing them through a medium with pores more minor than the particles of the fluid. This separation method produces a clarified fluid or solid filter cake as the desired product. Filtration is used in manufacturing, chemical processes, and producing electricity and sound. Cell-free mRNA production requires an IVT reaction to form a DNA template for in vitro transcription and capping of mRNA. Then, the mRNA is encapsulated with lipid nanoparticles (LNPs) to become a bulk drug product. As a new therapeutic modality, mRNA requires innovative solutions for its use in large-scale manufacturing. For instance, mRNA uses significant quantities of flammable materials that demand unique containment, storage, and disposal requirements that necessitate facility design features for hazardous area classification. In addition, the mRNA production workflow involves numerous raw material steps requiring unique formulations that are not readily available in GMP grade. This can impact endotoxin control and the overall quality of the mRNA product.

Encapsulation

While the significant mRNA manufacturing steps are similar for all current and emerging vaccines (and advanced therapies) that require encapsulation in lipid nanoparticles, many separation technologies and overall purification strategies are used. This means a high degree of variation can be expected in the final mRNA-LNP drug product. It is essential to monitor the purity of the mRNA and lipids throughout each step of production with a specific focus on the 5’ cap and poly-A tail regions of the mRNA, which are critical for ensuring translation and activation of an appropriate innate immune response. The quality of the lipid formulation is also essential for proper encapsulation and delivery. Due to the novel nature of the mRNA platform, it is critical to establish and maintain a robust library of materials and components certified RNase-free for use with mRNA manufacturing. This process is accomplished through rigorous, in-depth risk assessments of each proposed material vendor, including assessing the impact on patient safety and operator safety, facility cross-contamination potential, and the ability to meet regulatory expectations for quality control of the materials and assemblies.

Packaging

Packaging is critical in delivering mRNA, as it protects it from degradation during storage. This step involves the interaction of mRNA with lipids or polymers to form encapsulated or core-shell nanoparticles that are then used in a delivery system. The design and manufacturing of these systems must comply with regulatory standards and allow for scalable production. During process development, it’s essential to evaluate critical factors in the packaging stage that can impact mRNA quality and formulation. The mRNA production process is complex and requires an advanced understanding of its essential aspects. The upstream processes, DNA template preparation (plasmid DNA digestion, PCR amplification, and linearization), in vitro transcription using a DNA template, mRNA capping, and purification steps are all critical for producing high-quality mRNA at an industrial scale. In-process control and testing strategies should also be established to ensure mRNA is ready for clinical trial application. These include testing for mRNA length, mRNA integrity and accuracy of sequence, physicochemical characteristics, sterility, and endotoxin. Ideally, these tests can be performed on all batches of mRNA produced for clinical trials to support risk management decisions.