The mRNA vaccine, which is rated as an epoch-making innovation. Instead of injecting inactivated or inactivated viruses into the body, this method employs synthetic genetic fragments to emulate viral attacks and stimulate the immune system. This technology will be utilized extensively in the treatment of cancer and in other biomedical domains.
STEP 1: Extract DNA from cold storage
The DNA of SARS-CoV-2 (hereinafter referred to as virus) is extracted from the main cell bank. The DNA mentioned here will include a small DNA ring called plasmid, which is also the raw material of the vaccine, and will be extracted by technicians and stored in a small experimental bottle of-150°C The plasmids here are viral genes, and usually once exposed to this gene, the human body self will react biologically and construct viral proteins to form the immune system.
The technician will then inject the thawed plasmid into a batch of artificially adjusted E. coli, causing the E. coli to bring the plasmid into its own cells. Usually a small experimental bottle full of plasmids can be used to produce 50 million doses of vaccine.
STEP 2: Promote the growth and reproduction of cells
Cells containing E. coli and plasmids will be placed in an experimental bottle to grow and reproduce in a flask of a warm, sterile amber growth medium.
STEP 3: Fermentation mixture (bacteria)
The bacteria mentioned above will be given one night to grow and reproduce, then transferred to a 300-liter nutrient solution and stored for four days. During this period, the bacteria multiply every 20 minutes and replicate trillions of DNA plasmids.
STEP 4: Collect and purify DNA
After four days of fermentation, the researchers will inject a chemical into the bacterial cell wall, then purify the mixture, and eventually extract the remaining plasmid.
STEP 5: Quality inspection
The extracted plasmid will be compared with previous samples by technicians to confirm that the viral gene sequence of the newly produced plasmid has not mutated and can be used to produce vaccines.
STEP 6: Cut the plasmid
If the plasmid successfully passes the quality test, the technician will add another protein as an enzyme to the mixture. The main purpose of adding this enzyme is to cut the circular plasmid and the viral gene from their circular states into straight segments. The above process is called linearization, which takes about two days to complete.
STEP 7: Purify DNA
The technician will once again purify the already pure mixture to filter out any residual bacteria or plasmid fragments. The final production result was 1 liter of pure virus DNA. The technician will re-test the genetic sequence of the 1 liter of purified DNA and use it as a template for the next stage. So far, each bottle of DNA can be used to produce 1.5 million doses of vaccine.
STEP 8: Transport
Each bottle of DNA is frozen, bagged, and sealed before shipping, and its temperature is monitored by a small monitor at all times. Bottles containing DNA are placed in a container containing enough dry ice to ensure that all bottles are frozen at -20°C in the container.
STEP 9: Make the transition from DNA to mRNA
The main task of the production plant is to convert viral DNA into mRNA, which is the active component of the vaccine. Thaw the DNA and mix it with the part composed of messenger RNA. Within hours, the enzyme will pry open the DNA template and transform it into mRNA. The resulting vaccine will carry the mRNA into the body, and human cells will read the virus’s genes and produce their own viral proteins, also known as viral antibodies.
The mixture will be moved into a storage tank, and the useless DNA, enzymes, and other mixtures will be removed by filtration.
STEP 10: mRNA detection
Technicians need to repeatedly test the filtered mRNA to ensure its accuracy and the accuracy of the gene sequence.
STEP 11: Refrigerated, packaged, and reshipped
The mRNA package is frozen to -20°C, then shipped to the production plant, where the vaccine is made, and then the samples are sent back for testing.
STEP 12: Prepare mRNA
After receiving the package from mRNA, keep it frozen until needed.
STEP 13: Prepare lipids
At the same time, another step is under way to prepare lipids, a substance that protects mRNA from being destroyed when it enters human cells.
STEP 14: Develop mRNA vaccine
A set of 16-pump machines precisely controls mRNA and lipids, mixing them into lipid nanoparticles. When lipids and mRNA fragments meet, the electric level gathers them at nanoseconds, and the mRNA fragments are wrapped in nanoparticles to form a vaccine particle.
STEP 15: Prepare the vaccine bottle
Cleaning and high-temperature sterilization of vaccine bottles require 13 high-speed cameras are staring at the assembly line. Each bottle has to take more than 100 photos. Cracks, debris, and other problems can be quickly kicked off the production line.
STEP 16: Canned vaccine
The machine injected 0.45 milliliters of vaccine into a bottle and diluted it into six doses of vaccine. The production line can pack 575 bottles per minute.
STEP 17: Packaging, refrigeration, and testing
The injected vaccine is checked, labeled, and packed in a box. All boxes will be frozen for a few more days and cooled to an extremely cold temperature of -70°C. At the same time, the batch of vaccines will be sent for testing.
STEP 18: Package and transport finished vaccines
After weeks of testing, qualified vaccines are ready for transport. A thermometer is installed in the box to monitor whether the temperature is up to standard in real time.
The above is the whole process of disassembling the mRNA vaccine step by step. Although great breakthroughs have been made in the research and development of mRNA vaccines, key problems such as delivery, miss effect, and immunogenicity in the preparation of mRNA vaccines have not been completely solved, which needs to be strongly supported by continuously optimized production processes and key technologies.