Introduction
Imagine a world where a microscopic, yet fatal, virus that wreaks havoc on the entire globe completely alters the course of our lives. Oh, wait...that is the world we are living in right now. That was also the world we lived in during the Zika, Ebola, and Swine Flu eras. Unpredictable surges of viral infection throw billions of people off guard, who forced to wait years or even decades for a vaccine to effectively eradicate the spreading of the disease in a vast majority of places. Big biotechnology companies are implementing a novel and revolutionary method to create a COVID-19 vaccine: mRNA technology.
Terms to Know:
Proteins are molecules that do most of the work in cells and are responsible for carrying out almost every function in your body. DNA, which is short for deoxyribonucleic acid, is a double-stranded molecule, containing genetic instructions for making proteins your body needs. Synthesizing proteins your body needs to function is impossible to do without the help of mRNA. mRNA is a single-stranded molecule that takes genetic material from DNA in a cell’s nucleus to ribosomes, which are factories in the cytoplasm that make protein.
Protein Synthesis in Detail
A strand of DNA is copied onto a new molecule called the messenger RNA through a process called transcription
The new copy (mRNA) travels from the nucleus of the cell to the cytoplasm where all the ribosomes are. Ribosomes are machines in the cell that produce proteins.
The mRNA has the instructions for creating the proteins. The ribosomes “read” the mRNA through a process called translation, and by following the instructions, they build a specific protein.
The cell then expresses the protein, meaning that the protein is now available to carry out a certain function in the cell or body.
How do vaccines work?
To understand the science behind vaccinations, one needs to look at our normal immune response. When bacteria or viruses invade our bodies, their plan of attack is to multiply themselves, causing an infection. Red blood cells carry oxygen to other parts of the body and white blood cells, including macrophages, B-lymphocytes and T-lymphocytes, fight the infection. T-lymphocytes are memory cells that are responsible for triggering a similar defense response in case the same pathogen invades the body again.
In the past, vaccines typically contained the live, yet weakened version of the virus itself. Another approach is using an inactive virus or a dead form of the pathogen as a vaccine. However, in this case, several doses are required for full protection from the disease. Other types of vaccines include toxoid, subunit, and conjugate vaccines.
What is an mRNA vaccine and how is it different from the vaccines that were previously developed?
mRNA vaccines are a completely new realm of biotechnology. mRNA is a template for building proteins that fight diseases. Instead of your body producing its own mRNA, mRNA sequences are artificially synthesized so that cells would recognize the sequence just as if they were produced in the body. Focusing in on certain cells to produce disease-fighting proteins without injecting a weaker form of the real virus is one of the most significant advances in biotechnology.
The process for synthesizing mRNA vaccines:
Identify the DNA sequence for the particular protein that should be expressed
Design the code, which is the mRNA sequence, that will create that protein.
Reengineer the mRNA sequence to better express the protein and the desired mRNA’s physical properties
Inject mRNA sequence into the cells responsible for forming the protein. Accessing different cells calls for different delivery methods of the vaccine.
Once the mRNA is in the cells, the natural immune response kicks in.
mRNA Vaccines and COVID-19
When injecting mRNA directly into the body, natural enzymes will quickly rip the mRNA. To solve this problem, Pfizer and Moderna wrap the mRNA within an oily lipid nano-particle, which acts as a protective bubble. Due to the fragility of these molecules, the vaccine must be stored at very low temperatures. Moderna’s vaccine must be stored at -4 degrees Fahrenheit and will be able to be used for up to six months.
When entering the cell, the vaccine particles/bubbles bump into them, causing the mRNA to get released. Then the natural protein-synthesizing process begins and, in the case of COVID, produces spike-like proteins. The cell later destroys the mRNA and leaves no permanent trace of it afterwards.
Advantages
mRNA vaccines have many advantages compared to other types of vaccines including the lack of risk of using the real virus, shorter manufacturing times, and the ability of tackling multiple diseases at the same time due to its adaptability. Usually when a viral outbreak like COVID-19 occurs, by the time scientists can develop a vaccine and make it available to the general public, hundreds of thousands, if not millions of lives are already lost.
The readily available materials in laboratories and DNA templates allow for a much more cost-effective and simpler development of vaccines. Not only is the vaccine development faster than traditional methods, but also the rate at which mRNA vaccines shift into the clinic for initial testing is a lot higher. Unlike DNA vaccines, they do not need to enter the nucleus where the original cell’s DNA is in order to express the antigen. Frontiers in Immunology reports that “preclinical and clinical trials have shown that mRNA vaccines provide a safe and long-lasting immune response in animal models and humans.”
Conclusion
Moderna, BioNTech, Pfizer, and other biotech companies are advancing and leveraging mRNA technology to not only fight coronavirus, but also many fatal diseases and illnesses including cancer. There is a very high likelihood that prevention, if not a cure, to cancer will be based on mRNA research. As of right now, mRNA technology is disrupting the drug industry and is finding its moment to shine during the current COVID-19 era.
Bibliography
https://www.nejm.org/doi/full/10.1056/NEJMoa2022483
https://advances.sciencemag.org/content/6/26/eaaz6893