By Mark DaCosta- In recent years, the emergence of mRNA vaccine technology has marked a transformative chapter in the field of vaccinology. This innovative approach has not only revolutionised how vaccines are developed but has also played a pivotal role in the fight against the COVID-19 pandemic. Understanding the concept, development, manufacturing process, and the success of mRNA vaccines is crucial in appreciating their potential and future applications, including the exciting prospect of combating cancer. In this – Part III of this series of educational articles on how vaccines have changed the world – mRNA technology will be explored. To fully appreciate this groundbreaking medical development, you should read parts I and II of this series before reading this third part.
mRNA, or messenger RNA, serves as a crucial intermediary in the cellular process of protein synthesis. The concept of mRNA vaccines revolves around harnessing this natural process to stimulate an immune response against specific pathogens. Instead of using weakened or inactivated forms of a virus, mRNA vaccines provide genetic instructions to cells, instructing them to produce a harmless piece of the virus, known as a spike protein. This protein triggers an immune response, prompting the body to generate antibodies and memory cells.
The development of mRNA vaccines involves a meticulous process that begins with identifying the genetic sequence of the target pathogen. In the case of COVID-19, the genetic code of the SARS-CoV-2 virus was deciphered rapidly, thanks to advancements in genomic research. Once the genetic sequence is known, researchers can design the mRNA sequence that codes for the viral protein, such as the spike protein of the coronavirus.
The designed mRNA is then encapsulated in lipid – or fat –nanoparticles. Those tiny, microscopic envelopes protect it from degradation and facilitate its delivery into cells.
This lipid nanoparticle-encapsulated mRNA is the core component of the vaccine.
The ability to rapidly design and produce mRNA sequences for different viruses is a key advantage of this technology, allowing for swift responses to emerging infectious threats.
The manufacturing process of mRNA vaccines involves the synthesis of large quantities of the mRNA sequences and the formulation of lipid nanoparticles. The mRNA is produced using in vitro transcription, a laboratory technique that allows for the enzymatic synthesis of RNA from a DNA template. The lipid nanoparticles are then carefully crafted to encapsulate and protect the mRNA, ensuring its effective delivery into cells.
The scalability and flexibility of mRNA vaccine production have been highlighted during the COVID-19 pandemic. The technology allows for relatively rapid adaptation to new variants of the virus by modifying the mRNA sequence, demonstrating its potential to address evolving threats. This process contrasts with the long process of using whole viruses that must be slowly grown in cultures.
Once administered, mRNA vaccines prompt cells in the body to produce the viral protein specified by the mRNA sequence. In the case of COVID-19 vaccines, this protein is the spike protein of the SARS-CoV-2 virus. The immune system recognises this foreign protein as a threat and mounts an immune response, generating antibodies and memory cells.
If the vaccinated individual is later exposed to the actual virus, their immune system is already primed to recognise and neutralise it swiftly. The memory cells, created during the initial vaccination, “remember” the viral protein, providing a rapid, long lasting, and targeted defense against the virus. This mechanism of action is not only highly effective but also offers the advantage of a more rapid vaccine development process
The success of mRNA vaccines in mitigating the impact of COVID-19 has been nothing short of remarkable. The Pfizer-BioNTech and Moderna COVID-19 vaccines, both based on mRNA technology, demonstrated high efficacy in preventing symptomatic infection and severe disease. The speed at which these vaccines were developed and deployed played a critical role in the global response to the pandemic.
The widespread vaccination campaigns using mRNA technology have contributed significantly to reducing the spread of the virus, preventing hospitalisations, and saving countless lives. This success has solidified the role of mRNA vaccines as a game-changer in future pandemic response.
Beyond infectious diseases, the potential applications of mRNA vaccine technology extend to the realm of cancer immunotherapy. Researchers are exploring the use of mRNA vaccines to stimulate the immune system to recognise and target cancer cells. By encoding cancer-specific antigens into the mRNA sequence, these vaccines aim to train the immune system to identify and destroy cancerous cells.
This approach represents a personalised and precise method of cancer treatment, harnessing the body’s own immune system to combat the disease. While still in the early stages of research and clinical trials, early results have shown promise, opening new avenues in the ongoing quest for effective cancer therapies.
mRNA vaccine technology has emerged as a groundbreaking force in the field of vaccinology. From its rapid development to its success in combating COVID-19, mRNA vaccines have demonstrated their effectiveness and versatility. As ongoing research explores their potential applications against a spectrum of infectious diseases and even cancer, the future holds the promise of a new era in preventive medicine — one where the power of mRNA harnesses the body’s immune system to conquer diverse health challenges.
