COVID-19 vaccines and how they boost immunity

One of the fastest vaccines to be ever developed was for the COVID 19 virus, and along, a-raised a lot of fabricated deception. There are a lot of people around world dying due to COVID 19, mainly because of the fear to take the vaccines. It is very important to understand the working of these vaccines.  So without any delay let's first understand how many vaccines are there and how they function to boost immunity.  The below is the list of the currently authorised vaccines used for COVID 19 and their vaccine type. To know about the vaccines and types refer to the previous article on Vaccines and their functioning. 

1. Comirnaty (mRNA based vaccine)
2. Moderna COVID 19 (mRNA based vaccine) 
3. Covishield (Adenovirus vaccine)  
4. Sputnik (Recombinant adenovirus vaccine)
5. COVID 19 vaccine Janssen (non-replicating viral vector)
6. CoronaVac (Inactivated vaccine)
7. BBIBP-CorV (Inactivated vaccine)
8. EpiVacCorona (Peptide / Subunit Vaccine)
9. Convidicea (Recombinant vaccine from adenovirus type 5 vector) 
10. Covaxin (Inactivated Vaccine)
11. WIBP-CorV (Inactivated Vaccine)
12. CoviVac (Inactivated vaccine)
13. ZF2001 (Recombinant vaccine)
14. QazVac (Inactivated vaccine)

Now let's look further to define its design.

Some of the common vaccine types for coronavirus is the mRNA vaccine, the adenovirus vaccine, the recombinant vaccine, the viral vector vaccine, the peptide vaccine and the inactivated virus. 

1. The mRNA vaccines 

The chemical synthesis of this vaccine is very simple as a whole of virus or bacterium is not required to boost the immunity. The mRNA vaccine contains only the genetic information coding for a small part of the pathogen to train the body's immunity. These mRNA particles are coated with lipid nanoparticles to prevent damage to the mRNA. As this vaccine is very fragile it must be stored at a lower temperature of -70°C, if not it would fall apart before reaching the targeted destination.The below figure suggests the working mechanism.

(How the Pfizer-BioNTech Vaccine Works, 2021)

mRNA (messenger RNA) is a single-stranded molecule found in all of our cells. It transports the instructions for producing proteins from our genes in the cell nucleus to the cytoplasm (the main body). The information contained in mRNA is then translated into proteins by enzymes in the cytoplasm. With the case of the mRNA vaccine, it makes the human cell produce the viral protein in order to make the body respond and boost immunity. During this process as there is no viral toxin or viral multiplication the body gains immunity and is not affected with any infections. 

2. The adenovirus vaccines and  the viral vector vaccines 

The viral vector vaccine functions by using another harmless virus to transport the genetic material of the spike protein in the case of COVID 19. It uses gene modification to insert the genes coding for spike protein within a region called the vector in the transport cell. This type of vaccine also functions like the mRNA vaccine but just uses a pathogen for transport and not a lipid nanoparticle. The figure below depicts the working mechanism. Adenovirus is one type of an animal virus harmless to human, its vector is used to transport the spike protein gene within the humans cell in some COVID 19 vaccines.

(Ring, S., & Fourcade, M. 2021, BloombergQuint)

3.  The recombinant vaccine 

The recombinant vaccine uses the concept of joining together the specific DNA code into another species known as the adjuvant. This way the adjuvant presents the viral antigen from another virus. All together a combination of both the adjuvant and the antigen triggers no viral infections when in contact with a human cell but boosting the immunity. 

(The race for a Covid vaccine, 2021)

4. The peptide/ subunit Vaccine 

These vaccines are made of the antigen proteins present in the outer surface of a weak virus or bacterium. In the case of COVID 19 the subunit vaccine consists of a weaker form of the coronavirus's spike protein. These types of vaccines have a greater advantage than inactivated virus, as there is no risk with handling the pathogen and it can also efficiently induce immunological responses. 

(Subunit Vaccines, Calder Biosciences, 2021)

5. The inactivated virus 

Here the vaccine is killed or modified in a way that it doesn't replicate and cause any infectious response in the body. Although the virus is dead, antibodies will still be produced as the structure of the inactive antigen remains the same causing the production of antibodies. 

(X-Ray Virus Inactivation for Virus Vaccines - Precision X-Ray, 2021)

From the above information you were able to understand the vaccine mechanism. Now let's see what could be the possible side effects, and why these effects. 

1. Tiredness   

This is caused to store more energy for internal defence. As the body tends to fight against the virus there is a lot of extra energy needed to be invested.  So tiredness is a very common symptom to suggest the body is working a little extra than usual in the process of boosting immunity.     

2. Headaches

They are a common response to the immune system when molecules like cytokines are produced. These cytokines signal the body for inflammation, which thereby causes headaches.  

3. Muscle Pain 

This pain is caused due to inflammation triggered by protein cytokines produced by immune cells. The purpose of this inflammatory response is to remove tissue damaged by the viral body, which in the case of vaccines doesn't happen but just faking the system to trigger and boost immunity. 

4. Chills 

This is the pre-process by which the body tends to cause fever. It is producing heat within the system when the surrounding is cool. During this time there is a rapid muscle movement trying to generate more heat to aid the immune system with defence.

5. Fever

It is very common that our body responds to an infection by increasing the normal body temperature. But why? Well, when our body temperature increases it means our body has identified the invaders, and now is fighting back. To show whose place it is, the body temperature rises creating a favourable environment for our immunity, and at the same time making it harder for the pathogens to survive.

6. Nausea 

This discomfort associated with the stomach is highly linked with the defensive system. The immune system triggers nauseous responses to get rid of the potentially harmful ingested pathogen, before it reaches the lower digestive system to enter the bloodstream and to all parts of the body. This feeling again is one other indicator to show that the immune system is fully boosted to flush out the inactive or weak virus particles injected through a vaccine.

Are these side effects really that bad? There may be some allergic side effects due to our body's physical conditions, that doesn't mean the vaccines are completely inefficient with boosting the immunity. Sometimes there are cases without any of these side effects, it doesn't mean the vaccine does not work, but just that the way your body responds to the vaccine to boost immunity is different.