- Scientists have been examining messenger RNA (mRNA) vaccines for decades and have gained attention as an important way to tackle COVID-19.
- mRNA is a type of ribonucleic acid (RNA) necessary for protein production in the body.
- Despite the many benefits of using the mRNA technique for vaccine development, it comes with some challenges related to vaccine stability.
- COVID-19 vaccines developed by Pfizer/BioNTech and Moderna are mRNA-based vaccines that have demonstrated remarkable efficacy in clinical studies.
Vaccines help the body get ready to fight against foreign pathogens such as bacteria or viruses and prevent infection. Messenger RNA vaccines, also called mRNA vaccines, are a new type of vaccine that protects the human body against infectious indications. mRNA is the genetic material that informs the body how to make proteins.
mRNA vaccines came into the limelight as an important way to tackle COVID-19. These vaccines help the body’s cells to make proteins that trigger an immune response inside the body. This immune response allows the body to produce antibodies that protect it from getting infected when the actual virus enters the body.
Source: © Thodonal | Megapixl.com
Researchers have been evaluating mRNA vaccines for several years. The interest in mRNA vaccines has increased as they can be simply developed in a laboratory using readily available resources. This indicates that the vaccine development could be standardised and scaled up, making the process faster than the traditional methods of manufacturing vaccines.
How does the mRNA vaccine work?
Traditional vaccines require the introduction of inactivated pathogens or pathogen-specific molecules, for example, proteins or carbohydrates, into the patients’ body to act as antigens to stimulate the body's natural immune response.
On the other side, mRNA vaccine uses messenger RNA instead of part of bacteria or virus. mRNA is a type of RNA that is necessary for the production of protein in the body.
mRNA vaccines function by introducing a piece of mRNA that looks like a viral protein, usually a fragment of a protein found on the outer layer of the virus. As part of a body’s normal immune response, the immune system identifies that the protein as foreign and makes specialised proteins called antibodies. These antibodies help protect the body against infection by identifying individual viruses or other pathogens.
COVID-19 and mRNA vaccines
Last year, mRNA vaccines were the first to be authorised and found to be most effective against the deadly coronavirus (SARS-CoV-2), the virus causing COVID-19.
Copyright © 2020 Kalkine Media
Like the one that caused the ongoing pandemic, coronaviruses are named so because of the crown-like spikes found on their surface, called spike proteins. These spike proteins are the ultimate targets for vaccines.
mRNA based COVID-19 vaccines provide instructions to the body’s cells to produce a harmless piece of a protein that initiates an immune response. The body’s immune system identifies that spike protein as foreign and makes antibodies.
- Pfizer-BioNTech’s COVID-19 vaccine was found to be 95% effective in preventing COVID-19 in people aged 16 and older. Besides, the vaccine showed 100% efficacy in preventing COVID-19 in clinical trials performed in adolescents (12-15 years).
- Moderna’s vaccine was found 94% effective in preventing the COVID-19 in people aged 18 and older.
mRNA Vaccines: pros and cons
mRNA vaccines have several advantages over traditional vaccines. However, there are also some drawbacks to these vaccines.
Advantages of mRNA vaccines
- Lower costs and easy production are the biggest advantages of mRNA vaccines, especially in an emerging indication such as COVID-19.
- Because mRNA contains no strain of bacteria and virus, it is non-infectious. Therefore, no potential risk of COVID-19 infection from the vaccine.
- mRNA vaccines can be safer as compared to traditional vaccines.
Disadvantages for mRNA vaccines
These vaccines are delicate and can degrade easily under normal conditions. For this reason, the vaccines need to be stored under specific conditions.
For example, Pfizer/BioNTech and Moderna vaccines must be kept in cold storage and sometimes ultra-cold storage. For prolonged storage, the Pfizer/BioNTech must be stored at ultra-cold freezer at temperatures between -80°C and -60°C.
This poses an issue with the distribution of vaccines and also limits the storage. For example, only facilities with appropriate refrigeration capabilities can store such vaccines.
After its success in combating COVID-19, experts are confident that mRNA vaccine technology can allow one vaccine to protect against several indications in the future. Thus, it will decrease the number of shots needed to protect against vaccine-preventable diseases. Besides, other than vaccines, cancer research has used mRNA technology to activate the immune system for targeting specific tumour cells.