Why The Oxford Chadox1-Ncov-19 Vaccine Is So Promising

Why The Oxford Chadox1-Ncov-19 Vaccine Is So Promising

And The Concept So Exciting ***Original Artwork by Physician Artist Dr. Maycie Elchoufi***

The Oxford ChAdOx1- nCoV-19 vaccine holds a lot of promise, not only as a way to deal with COVID-19 but also with future viral outbreaks. The method of using a viral vector as a way of presenting antigens into the human body allows for a very novel and fast way of getting new vaccines.



Let’s say Virus X has caused an outbreak of a disease and you need to make a vaccine to fight it.



Classically, to get a vaccine against it, you have to introduce a piece or all of virus X into the human body. You could also use another virus (a piece of it or the whole virus) from the same family that Virus X comes from. Now if you use the whole virus, you need to either kill it, inactivate or weaken it so it does cause disease.



Once the virus or a piece of it gets into the human body, the immune system recognizes it as something foreign and builds antibodies against it. These antibodies last a long time so the next time you get an infection caused by Virus X, the antibodies attack the virus and inactivate it before it makes you sick. Thus, you can use it to prevent disease in those who haven’t fallen sick yet.



The Oxford team used another method. Instead of using the SARS-CoV-2 virus or even a piece of it, they use a vector to get a part of SARS-CoV-2 into the body. The vector they use is another virus. This virus is called an Adenovirus and they use the type found in chimpanzees.



Once they have that adenovirus, they modify it to the point where it is unable to replicate anymore or make any mammal sick. It becomes basically a shell. Once they have that adenovirus shell, they get the RNA from the SARS-CoV-2 virus and get out the part of the RNA that makes the Spike Protein that SARS-CoV-2 needs to get into the cells of the lungs. Once that piece of RNA gets into the adenovirus shell, it causes the building of the Spike on the outside of the shell. (Remember, RNA and DNA code for the building of proteins. If you get them into the right environment, and they have the right materials, they’ll build the proteins they are coded for).



So now the team has a modified, inactivated adenovirus with the Spike Protein of SARS-CoV-2. When they inject that into the human body, the immune system sees the Spike Protein and recognizes it as something foreign. The adenovirus shell does not cause any immune reaction, only the spike. Antibodies are then made against the Spike Protein.



Now since this is the Spike Protein from SARS-CoV-2, if the virus should attack, there are already antibodies against that. Since that is what SARS-CoV-2 needs to enter the cell, once the antibodies attack and destroy it, it will be unable to enter the cell and thus unable to cause COVID-19.



Using the spike protein is genius because in all the variants of the virus found in the bat RaTG13, in pangolins, in SARS or MERS, the Spike Protein has stayed largely constant.



The piece or part of the virus used has to stay unchanged over time to ensure the vaccine works for a long time. There is always a risk that the virus can change that part through mutation.



The question now is whether the modified adenovirus + spike protein contraption will get the human body to mount a powerful enough immune reaction in humans. It did in monkeys.



Also, since they are using the whole virus, there is no need to find out what works best - killing it off or weakening it. Since the team already had the adenovirus shell, all they needed was the genetic info from SARS-CoV- 2 and they could get the RNA sequence for the Spike Protein and plug it in.



This also means they could do this for other diseases. They can even do this for any viral disease that may break out in the future, as long as they can isolate the virus from bats, birds or pigs and sequence the genomes.



That is why the Oxford ChAdOx1- nCoV-19 vaccine is so promising and the concept so exciting. 


***Original artwork created by physician artist Dr. Maycie Elchoufi***

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