Behind the mRNA vaccine technology

 The two vaccines that are currently leading the race for the coronavirus vaccine are the m-RNA vaccines. mRNA is the messenger RNA. This m-RNA, which is essential for the functioning of cells, acts as a messenger.

 RNA is formed by following the genome or DNA of a cell in a biochemical reaction called transcription at the nucleus of a cell. 



The mRNA is made by cutting that RNA into another type of reaction called translation, which is needed to make it suitable for making proteins.

 In this process, not exactly proteins are formed by altering mRNA. They carry the genome or DNA codes in the nucleus to the cytoplasm. 

There, based on the code present in mRNA, different types of amino acids combine to form thousands of different types of proteins. 

It's a lot like making a garland with beads of different colours or sizes. As our brains tell us which beads to add when making a garland, amino acids are added according to the code stored in the mRNA when making proteins.

 How did this m-RNA, an essential element of the cell, get involved in the vaccine effort?

The purpose of the vaccine is to train our body's immune system to fight specific pathogens. 

And to do that we need to apply something to our body that will identify the germ in our body without causing any harm. 

Edward Jenner, the founder of vaccine science observed it in the eighteenth century. He noticed that cowpox-infected cowboys do not have smallpox. 

It was from this idea that he contracted the smallpox virus, or smallpox, which was then a deadly disease. 

This was made possible by the fact that the smallpox virus has a lot in common with the cowpox virus. Again since the cowpox virus cannot cause serious diseases in the human body. 

Later, however, the smallpox vaccine was developed at numerous times. One by one new technology is added to vaccine science. 

Vaccines are used one by one: inactivated germs, such as rabies and poliovirus vaccines have been used, alive but ‘attenuated’ or anaesthetized germs, such as BCG, measles, mumps and rubella vaccines; Bacterial toxins, such as diphtheria and tetanus vaccines, are also used. 

On the other hand, with the advancement of gene technology, new levels of recombinant protein and conjugate vaccines such as hepatitis-B, Hib, whooping cough, pneumococcal and meningococcal vaccines have been developed.

Regardless of the type of vaccine, the key to the effectiveness of the vaccine is: to have pre-existing immunity against a single germ. A part of antibodies made against germs. 

This immunity can be against inactivated or anaesthetized bacteria or viruses or against any protein or polysaccharide that is part of the body's immune system. 




Thanks to gene technology, the proteins of one bacterium can easily be made into another microorganism or animal body. 

From this idea came the idea of ​​DNA or RNA vaccine. Since it is possible to make RNA artificially and commercially outside the cell, it is not impossible to make millions of doses of the mRNA vaccine. 

In 1990, it was first reported that mRNA was used to make the desired protein in animals. At that time, the study was started to use it as a cancer vaccine, not a pathogen. 

However, due to the successful delivery of the mRNA vaccine to cells, unwanted reactions in the body, and doubts about the stability of the vaccine, little emphasis was placed on the study.

Over the past decade, there has been much progress in research on mRNA delivery in cells and its sustainability in animals. 

By modifying the structure and code of mRNA to increase its durability, and by encapsulating it in lipid nanoparticles, mRNA is being delivered to the inside of the cell.

 The mRNA vaccine has been successfully tested against a variety of pathogens in rats, rabbits and humans before the Corona epidemic. 

Even the first-stage clinical trials began with many mRNA vaccines; These include influenza, Ebola, Zika and Chikungunya vaccines. 

However, no other vaccine has reached the stage where research has been done on the mRNA vaccine of COVID-19 coronavirus. 

It is needless to say that the accumulated experience of the last decade is behind this incredible rapid progress.

The urgent need to control the corona epidemic has caused a great stir in the vaccine world. At present more than one hundred vaccines are being worked on. 

There are a total of 54 vaccines in the clinical trial. These include all conventional vaccine types, from adenovirus-based vaccines and mRNA vaccines. 

Adenovirus-based vaccines, such as the Oxford vaccine in the United Kingdom, the Sputnik-V in Russia, and the CanSinoBio-vaccine in China, have been at the centre of discussions so far, passing the first and second stages of clinical trials. 

Moderna's mRNA vaccine was also at the forefront. But at the moment, Pfizer-BioNtech's mRNA vaccine is at the forefront. 

In the third phase of the clinical trial, the vaccine was administered to 43,000 people and found to be about 95 per cent effective in controlling the infection without any significant side effects. 

Moderna's mRNA vaccine has shown similar success. On top of that, Moderna's mRNA vaccine has the added benefit of preservation. 

The Pfizer-BioNtech vaccine has to be stored at a temperature below minus 60 degrees Celsius, whereas, the Moderna vaccine lasts up to a month in a normal refrigerator and up to six months in a deep freezer (at -20°C).

Pfizer-BioNtech has already applied to the FDA for 
authorization for emergency use. Moderna is also expected to apply in several weeks.

If all goes well, two mRNA vaccines are likely to be approved for the first time by the end of this year. There are many challenges even after approval. Production, quality control, storage and supply of vaccines on a large scale. 

Moreover, passing the clinical trial and getting approval is not the end. It takes years to determine the effectiveness of a vaccine, its side effects, and how much protection it can provide.

 Post-application practical experience is also required outside of clinical trials. Regular monitoring of vaccine effectiveness is required.

mRNA-vaccine is the name of new technology in the prevention of infectious diseases. Work on this type of vaccine has been going on for a long time. 

But so far there is no example of successful application of such vaccine in the world. If successfully applied, this vaccine of COVID-19 coronavirus will bring a new revolution in vaccine technology.

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