This is how corona vaccines work: the advanced technologies at the base of the vaccines

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The race to complete the development of the vaccine for Corona is in its final stages, with the first vaccines of the American modern, the British Astra-Zenika and the Chinese Kensino expected to be ready for January. Although it is not yet clear how long the vaccines will protect from the moment of injection into the body, it is important to know how the injection prevents infection with the corona virus.

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To answer this question, one must first understand the initial stages of infection: the corona virus carried on shards of saliva, penetrates through the nose and pharynx, attaches to the cells of the respiratory system, where it penetrates the cell nucleus and begins to replicate. During this time, hundreds of thousands of white blood cells flock to the site, the first of which are the soldiers of the first line – the antibodies, which adhere to the invading virus, neutralize it and mark it with a kind of flag that signals the immune system to reach the site to destroy the virus.

After the initial encounter between the antibodies and the corona virus, a kind of “personal signature” is formed in which the body begins to recognize the corona virus, and produce appropriate antibodies, which in the next encounter – will soon neutralize the virus that has penetrated, preventing it from spreading and infecting cells in the body.

This is exactly what the vaccine does: once it is injected into the body, it “steals” on the immune system that it is ostensibly a real virus – even though there is no live virus in the vaccine. The body is in a hurry to create antibodies that will prevent the coronavirus’ next penetration of its ability to infect the body’s cells.

The vaccine “cheats” on the immune system and simulates infection with a real virus (Photo: Shutterstock)

Some vaccines, such as the Chinese Sinovac vaccine CoronaVac vaccine, are based on basic virus-killed technology. This vaccine, for example, contains particles of “lifeless” corona virus, which has no ability to cause disease. These particles are basically proteins that are introduced into the body, which the immune system of the person vaccinated against recognizes as the virus itself, and thus creates antibodies against it. Most of the other vaccines against corona, however, work in another vector mechanism, or in Hebrew: Nasa. This is also the basis for the Israeli vaccine developed at the Biological Institute.

And this is how it works: The vaccine consists of the stomatitis and vascular virus, VSV, which belongs to a family of viruses that cause diseases in animals. However, it is rare for the virus to cause infection in humans. VSV viruses have also been developed in laboratories in the past to serve as a platform for the production of a variety of vaccines against viruses, including the Ebola virus, HIV virus, and Congo fever.

In the VSV virus, scientists modify a protein called VSV-G, which serves as a viral platform. This protein of the engineered virus, is known to be a significant factor in the destructive ability of the virus in the body. Thus, the virus becomes a kind of “skeleton” that can serve as a carrier of other virus particles that will make the body “think” that it is a real virus, produce antibodies against it that will be stored in the body, and attack the real virus in case of infection.

In the present case, the Israeli scientists created a hybrid creature that contains the engineered VSV virus from which they removed the violent G protein. Instead of this protein, the scientists injected the protein S protein from the corona virus COVID-19, which is responsible for creating an immune response as if it were the real virus. As a result, the engineered virus does not cause disease, but causes the body to produce antibodies – thus vaccinating the body against corona.

Another way to carry a carrier-based vaccine was created by the American company Modern, which is also in a very advanced stage of development: the vaccine called mRNA-1273 is called a “messenger RNA vaccine”, which upon entry into the body, eliminates the ability of the corona virus to enter cells. The messenger RNA in question, when present in the body, prevents the formation of a protein called Spike, the same protein that is found in the outer shell of the corona virus and gives the virus the appearance of a “crown”. The same “crown” also gave the corona virus its name.

The same Spike protein is needed for the corona viruses to attach to human body cells. The vaccine, prevents the same adhesion, prevents the virus from penetrating the cell, moving towards the nucleus of the cell and replicating.

The vaccine from Oxford University and the Astra-Zenika company also works through a carrier. The vaccine, called AZD1222, contains an attenuated version of viruses that cause colds in chimpanzees – but not in humans, on which the scientists “dressed” one of the corona virus proteins COVID19.

With the injection of the vaccine into the body, in which the cold viruses in chimpanzees and corona protein, the body is convinced that a real corona virus has entered it. It summons the antibodies that neutralize the vaccine, but create an immune memory. Within two weeks, copies of such antibodies against the corona virus are formed, and so in the next infection with a real corona virus, they will attack it, neutralize it and not allow it to infect the person and get the serious disease.

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