Do you know that most human medicines, including vaccines, are small molecules or proteins? For the last two decades, there’s been broad interest in RNA – based technologies for the production of therapeutic and prophylactic vaccines.
According to clinical and preclinical trials, mRNA provides a long-lasting and safe immune response in human models. In this light, we summarize the current research progress on mRNA vaccines which have the potential to become powerful tools against infectious diseases. As such, this article will highlight the bright future of the design and applications of these vaccines.
But first, what is an mRNA vaccine and how does it work?
I bet you know how a traditional vaccine works. Well, it introduces inactive pathogen or pathogen-specific molecules like protein or carbohydrate into the human body. These molecules act as antigens that stimulate the body’s natural adaptive immune response.
The response prepares the immune cells to attack any virus or disease-causing cells that may appear in the future. Well, that’s not the case for mRNA vaccines.
Well, the mRNA vaccine doesn’t introduce viruses or antigens into your body. Rather, it prompts the body’s cells to produce a disease-specific antigen protein. Once the vaccine is introduced into the body cell, the engineered mRNA transcript is translated into protein by the cell’s ribosome like any other RNA transcript. When this antigen protein is expressed on the body cells’ surface, the immune system recognizes it as foreign and thus works to attack these antigens prompting the system to defend itself against future exposure to this disease.
And yes, like traditional vaccines, mRNA vaccines are administered to the body through nasal sprays or injections. The injection may target the muscle, bloodstream, skin, lymph nodes, or specific organs and tumors.
The Advantages of mRNA Vaccines
The ease and lower costs of production may be the biggest advantages of mRNA vaccines, especially when dealing with emerging diseases like COVID-19, Ebola, and Zika virus. The history of mRNA vaccines shows that they’re safer than traditional vaccines.
But how?
The mRNA transcript degrades and disappears within hours, leaving an encoded protein that performs its functions. These proteins too are also degraded within days. The effect is a reduced risk of multisystem inflammatory syndromes and other risks associated with the introduction of foreign agents in the body.
The Application of mRNA Vaccines
The world’s first mRNA vaccine has begun its rollout after being produced at unprecedented speed to combat the coronavirus pandemic. The second vaccine is also hot on its heels. The two vaccines are made by Moderna and Pfizer/BioNTech and are the first ones to be approved for use by humans. In the clinical trials, these vaccines have an efficacy rate of 94% in preventing people from getting ill from Covid-19.
The mRNA vaccines are very specific. For instance, let’s assume that a person who isn’t vaccinated catches the Covid-19 virus. Their body will produce antibodies that prevent the virus from entering the body cells. They may also produce antibodies with less impact or ones that aid the virus to get into the body. That’s not the case with the mRNA vaccine. It’ll only trigger an immune response to the virus’s spike protein, the component of the viral membrane that allows the virus to attack our cells.