What are mRNA Vaccines?
Vaccines play a critical role in the health and well-being of our society at large. They help drastically reduce the contraction and spread of infectious diseases, in turn limiting the severity of harm caused. Vaccines not only help protect the individual receiving the vaccine, but also everyone they come into contact with. We’re all in this together.
This article will explain a newer tactic of vaccine delivery—known as “mRNA vaccines”—it’s use in recent COVID-19 vaccines, how it works, how it differs from most traditional vaccines, and how the technique is being used to help our bodies fight more and more disease types.
mRNA Vaccines vs. Traditional Vaccines
Traditional Vaccines
Our immune systems are amazing! They detect viruses, bacteria, and other organisms that can cause us harm, and fight them. When we get a temperature, a sore throat or a runny nose, that’s our bodies reacting to a virus, increasing our metabolism, and waging war against the intruder!
Traditional vaccines work by introducing our bodies (by an injection, pill, nasal spray, etc.) to an inactive or weakened form of the very virus or bacteria we are seeking to protect against. Our immune system recognizes this foreign inactive or weakened pathogen as being problematic, triggering our immune system to build appropriate antibodies to help fight off and neutralize the infection. Crucially, memory cells are also made, which help our immune system remember previous infections and how to respond to them — so by introducing our bodies to an inactive or weakened form of the infection, we are essentially building immunity.
mRNA Vaccines
mRNA vaccines utilize a different tactic. mRNA vaccines use genetic material, or what can be thought of as ‘a set of instructions’ for our immune cells. Once the vaccine is injected into our body, the mRNA makes its way into our cells and instructs the cells to produce what are called “spike proteins” — an important component to both the virus and vaccine.
Spike proteins protrude from the surface of a virus. They are what the virus uses to attach to and infect our healthy cells. They’re also the critical piece that mRNA instructs our healthy cells to make in order to trigger an immune response. Spike proteins pose no threat on their own. They can also look different depending on the virus, so you need to first map the virus and figure out their design so you can accurately replicate them using mRNA.
“Previous research revealed that coronaviruses invade cells through so-called "spike" proteins, but those proteins take on different shapes in different coronaviruses. Figuring out the shape of the spike protein in SARS-Cov-2 is the key to figuring out how to target the virus, said Jason McLellan, senior author of the study and an associate professor of molecular biosciences at the University of Texas at Austin.”
Once our cells produce these spike proteins on their own surface, our immune system recognizes them as foreign, knows they don’t belong, and springs into action, creating antibodies to neutralize and disable them. If a person is then infected with the virus, our immune system, with the help of memory cells, recognizes these spike proteins and is already prepared to protect us with the right antibodies.
What are the advantages of mRNA Vaccines?
- Safety
Because an mRNA vaccine doesn’t contain a live virus, the recipient can’t get infected with the vaccine. Research, development and manufacturing are also safer, as containing a live virus isn’t a concern with this method. - Easier to Manufacture
Traditional vaccines have to be grown and cultured inside live cells (using eggs or cell lines in many cases) and require harvesting and purification. This process can be time-consuming.
mRNA is synthetic and can be produced and replicated much faster and easier, saving valuable time.
Takeaway
Both traditional vaccines and mRNA vaccines aim to accomplish the same thing — prepare and train our immune system to recognize harmful foreign viruses and bacteria, create memory cells that remember what actions to take, and respond with antibodies to fight them off before they can cause harm — they just have different approaches in getting us there.
mRNA vaccines, both presently and their use case in the future, are undoubtedly exciting. However, we are still in the relatively early stages and need your help. Currently, mRNA is being utilized in several COVID-19 vaccines, with promising results. Vaccines are most effective the more people are vaccinated, helping to achieve herd immunity.
Scientists and researchers have studied mRNA for a while now, from use in vaccines to treating cancer and cancer research. So, while the technology isn’t unheard of, its approval in vaccines is: with the Pfizer-BioNTech COVID-19 vaccine and Moderna COVID-19 vaccine — both approved for emergency use authorization in December, 2020 — marking the first licensed vaccines using mRNA for infectious disease. With this exciting technology delivering impressive efficacy and safety results, we’re likely to see more and more applications in a wide range of diseases.