Pfizer COVID-19 Vaccine

Pfizer COVID-19 Vaccine
26 May 2021
by
in Blog

On the 25th of May 2021, I had the Pfizer (Comirnaty) COVID-19 vaccine which is the vaccine which is recommended to people in Australia under 50. Our vaccine roll-out in Australia has been fairly slow but I received the Vaccine before the general public as I have an underlying medical condition which puts me at a higher risk of COVID-19 complications.

In this post I wanted to talk a bit about my experience in getting the vaccine, side effects and my general views. General disclaimer applies that I am not a doctor so this information is just for general discussion, you should always seek medical advice, and of course your experiences may be different to mine.

 

The Process

I received the vaccine at Monash Health which is a major healthcare provider in the South East Suburbs of Melbourne, Victoria, Australia. I booked in through the COVID-19 hotline and within 5 minutes they had asked if I was eligible, took my details, and gave me options of places nearby where I could have the injection and booked me in at the place of my choice.

I booked about 1.5 weeks out, so the time was fairly quick between me booking an appointment and me actually having the vaccine. To have the vaccine I went to Monash Health, and was given a QR code to read some information about the vaccine (which was also available in printed code), I was checked in and had to give proof of ID, Medicare card and proof of eligibility. Following that I was directed to a person who told me where to wait, and a nurse then came and got me to give me the injection.

The time between checking in, and having the vaccine injection was about 5 minutes so was very quick. Before I had the injection I was given information about it, side effects and so on, and once I had the jab the exact time I received it was recorded in a database and I was directed to a waiting area.

I waited until 15 minutes in the waiting area until 15 minutes from the time I received the jab had elapsed, and my name was called (as I assume it came up in the database) and I was asked if I was OK, if so I could go and book my second appointment (about 3 weeks from the 1st) and then go home.

 

Side Effects

In terms of the side effects, as I write this (the day after) I have had very minimal side effects. When I had the injection I had some localised soreness (the jab itself was in the muscle in my arm) which got better after a few hours.

The next day however, my arm felt like a lead weight and was quite sore at the point of injection (but otherwise I have not had any other symptoms).

Update (late June 2021): I had my second booster which was as seemless as the first. The only side effect I had was that I got a sore arm and felt a little bit of nausea which passed within about 1 day.

 

What is it and how does it work?

The Pfizer (Comirnaty) vaccine consists of a lipid nanoparticle and a strange of genetic information known as Messenger RNA (mRNA) which codes for a mutation of the spike protein of the SARS-COV-2 Virus.

It should be noted that the vaccine does not contain the full virus, only the genetic information which codes for a mutated form of the spike protein and not the full virus.

The lipid nanoparticle which is an enveloped, is essentially a drug delivery vehicle which protects the mRNA. When the vaccine is injected, the nanoparticle bumps into cells and fuses to these releasing the mRNA into the cell.

The mRNA is a sequence of ribonucleic acids which is genetic information (coded as A, U, C or G) which form codons (which are a grouping of three ribonucleic acids) which is essentially the blueprint for the cell to make proteins. The sequence of this mRNA is read by the ribosome within the cell, and based on the code, a sequence of amino acids are strung together to form a protein (in this case the modified spike protein of the SARS-CoV-2 virus).

 

Figure 1: Illustrates how a ribosome a mRNA and lots of tRNA molecules work together to produce peptides or proteins. Illustration by LadyofHats

 

The ribosome within the cell creates these spike proteins, and three of these proteins form together to form a combined spike protein. Some of these spike proteins move to the surface of the cell, otherwise when the cell dies the spike proteins are released.

There are a range of different immune system cells within the body, which all have different functions. One cell is called a T-Cell which is like a warning system for the body. There are multiple types of T-Cells but one of these is called a helper T-Cell (CD4+) whilst the other is called a Killer T-Cell (CD8+), when the helper T-cell detects the spike protein on the surface of the infected cell it releases a range of biological signalling chemicals (i.e. cytokines) which signal to other immune cells that an immune response is needed in that specific area. This signaling may trigger B-cells or Cytotoxic T-Cells.

At the same time, some spike protein may also be circulating freely within the body which is picked up by an antigen presenting cell (including Dendritic cells, Macrophages, Langerhans and B Cells.). These cells may also pass these spike proteins to Helper T-Cells which start the signaling pathway as per the above.

Once the helper T-Cell has activated other cells, it will ‘present' the antigen it collected to a B-Cell, this is a special type of immune cell which basically generates antibodies which bind to the antigen. The antibodies trap the cells in large clumps which helps the immune cells target them. Furthermore they can also signal other immune cells to destroy the item. The benefit of B cells is that in addition to generating the antibodies, they also remember the antibody so that in the future rather than learning how to make the antibody for a specific antigen, it already knows how and can act much faster.

The very last part is a special type of cell called a Cytotoxic / Killer T-Cell. This is a T-Cell which contains a specific antibody on the surface which is specific for a given antibody. When the cytotoxic T-cell identifies this antigen a pathway is triggered which may result in the cytotoxic T-Cell killing the cell affected by the virus.

All of the above is a very summarized form, and of course you should be aware that there are many different molecular pathways that take place, and the response if far more complicated than this. But nonetheless it is an incredible pathway that takes place as part of the human bodies immune response.

 

Myths about the vaccine

There are so many myths about the virus from mind control to 5G, I am not going to focus on any of those but one of the most common I have heard is that by the genetic information being injected it is changing your DNA forever. That is not the case, and whilst a full description of RNA vs DNA is outside of the scope of this article, for the purposes of humans the genetic information is stored as DNA, DNA is converted to RNA and this then needs to be processed into a form called messenger RNA (mRNA). The mRNA is used by the body to create proteins on a regular basis, but messenger RNA degrades fairly quickly, and is not incorporated back into RNA and subsequently DNA so although genetic information (in the form of mRNA) is being injected into your body, it degrades quickly and does not get added to your DNA / genome.

 

TLDR

Had the COVID-19 (Pfizer) vaccine which was a seamless experience, a bit of a sore arm afterwards but very few symptoms. How the vaccine works is fascinating in that it takes and packages the genetic information (mRNA) to code for a modified spike protein from the virus and puts this in a in a lipid nanoparticle. When you have the injection the particle fuses with your cells and releases the genetic information which is read by ribosomes which then start to make one limited component of the virus (the spike protein). This spike shows up on the surface of infected cells (and in the body) and special cells in your body (T-Cells) identify this as foreign and sound the alert for other cells to come along and produce antibodies (B-Cells). The antibodies to the spike protein (antigen) are used to help the body identify infected cells which it should kill, as well as to neutralize the foreign protein but more importantly the antibodies are remembered by long lived plasma cells and Memory B-cells so that if you are infected in the future your body knows how to make the antibodies and can mount a much faster response.

It is quite a remarkable process, and from what I can tell it should make creating future vaccines much quicker because in the future you could just replace the genetic information with that of the next virus spike protein and after clinical trials, regulatory approval et al you are good to go.

 

References

https://en.wikipedia.org/wiki/Pfizer–BioNTech_COVID-19_vaccine

https://commons.wikimedia.org/wiki/File:Ribosome_mRNA_translation_en.svg

https://www.nytimes.com/interactive/2020/health/pfizer-biontech-covid-19-vaccine.html

https://www.healio.com/hematology-oncology/learn-immuno-oncology/the-immune-system/components-of-the-immune-system

https://theconversation.com/coronavirus-b-cells-and-t-cells-explained-141888

https://www.who.int/docs/default-source/coronaviruse/risk-comms-updates/update52_vaccines.pdf?sfvrsn=b11be994_4