The Pfizer COVID-19 Vaccination explained

I am not going to tell you that you should get the new Pfizer COVID-19 vaccine because it is not my place. Only you can make that decision for yourself and a loved one in your care. However what I can do is explain how the vaccine works and counter some of the prevalent misinformation out there so you can make a more informed decision. 

The Sars-CoV-2 virus causes Coronavirus disease 2019 (COVID-19), which like all viruses needs a way of penetrating its target cell. To do this, it is studded with spike proteins, which bind to an enzyme attached to the cell membranes found in its host. In the case of novel coronavirus it binds to an enzyme called ACE-2 (angiotensin converting enzyme 2) which can be found on the surface of cells found in our lungs, arteries, heart, kidney, and intestines. The virus then penetrates the host cell turning it into a mini factor for producing copies of itself. So what does this have to do with the new Pfizer vaccine, and why is it imported to know about the spike proteins which cover this virus? To understand why you must first understand the central dogma of molecular biology which explains the flow of genetic information within a biological system. 

The very basic, to the point of being incorrect, version of this is that DNA goes to RNA which goes to protein. DNA is the blueprints of life that contains the instructions for, among other things, making proteins. It does this in two key stages – transcription and translation. In transcription the information in the DNA is coverted into a small, portable RNA messages or messenger RNA (mRNA). This mRNA then travels from where the DNA is in the cell to where it can be translated into specific proteins. An analogy of this process would be asking a friend for their spaghetti bolognese recipe. You call your friend on the phone who represents DNA and write down their instructions, which represent the mRNA. This is like transcription, where DNA is transcribed into mRNA. You then cook the food based on these copied instructions, translating your copied instruction into a lovely meal that represents the proteins being synthesised. 

The Pfizer vaccine is mRNA based and is different from conventional vaccines, which are produced using weakend forms of the virus you are trying to immunise against. It works by having the genetic information in mRNA form for the coronavirus spike protein. When it enters a cell, the cells own molecule machinery reads this mRNA code and translates it into coronavirus spike protein. The mRNA from the vaccine is eventually destroyed by the cell, leaving no trace. The vaccine is engineered to have a special tag that tells the cell to migrate the protein to the cell’s surface and stick into very special immune recognition tools. The immune system then recognises these protruding spikes and spike protein fragments and you body starts producing antibodies and even start killing infected cells. What is important to note is that the vaccine does not contain the full instruction for creating a fully formed coronavirus particle. It only contains the information required to produce the spike protein which on its own is useless other than provoking an immune response. I find some irony in the sense that the mechanisms that virus used to highjack cells are the same used by the vaccine to help end this pandemic. 

This new mRNA vaccine has some benefits and some drawbacks. As anyone who has worked in an RNA lab before will tell you, RNA is ripped to shreds by enzymes found practically…well everywhere. As a result, the scientists working at Pfizer had to think of a way of protecting their mRNA-based vaccine. Their solution was to wrap it in a bubble of the same oily substance which makes up our own cells. However, the downside to this is that their bubble is extremely fragile and will quickly fall apart at room temperature, which is why these vaccines are kept at extremely low temperatures. The benefit of mRNA vaccine is the speed at which they can be produced. Unlike conventional vaccines, which are produced using weakened forms of the virus, RNA vaccines can be construed quickly using only the pathogen’s genetic code, we can literally print mRNA in the lab. What once took between years to accomplish now can be down in as little as a week. 

The new vaccine was developed and approved in less than a year which naturally has cause a fair amount of mistrust in a population who are already skeptical of vaccines due to the bogus MMR vaccine scare of the late 90s. After all, traditional vaccine development is a slow and laborious process taking on average 10 years. So how has it been possible to develop a vaccine from scratch in such a short amount of time? The answer is a combination of urgency and money. 

Both public and private cash have been poured into the race for a Sars-CoV-2 vaccine, allowing pharmaceutical companies to take greater risks at the early stage of development. Rather than performing clinical trials in sequence they had them overlapping making the process much faster. They also began manufacturing the vaccine in parallel with the clinical trials, gambling that they would show the vaccine to be safe and effective. They also changed the way they presented their data to get their vaccine approved. Normally companies wait until all the date is in before submitting in one go for approval due to it being an expensive and risky process. However, with the Pfizer COVID-19 vaccine, they accelerated the process by releasing information to the regulators as it was acquired. 

In total over 44,000 people in over 150 clinical trials have shown that the Pfizer vaccine is 95% effective at preventing disease when measured a week after participants are given a second dose. The trials also revealed that some recipients experienced pain at the injection site, along with fever, fatigue, sore muscles, and headaches – although these symptoms usually lasted for only a few days and were generally not considered serious. Such symptoms are good evidence that your immune system is reacting to something, which is the point of vaccines and is required to work. 

At this moment in time, there is no quick way to determine how long immunity to the virus will last, and the researcher will be monitoring this closely in the coming months and years. There is also no data yet on how the vaccine will fare in children and pregnant women. 

As I said at the beginning, it is not my place to tell you to get the new Pfizer COVID-19 vaccine, but what I will say is that when it is offered to me I will accept it. I want things to go back to normal and the harsh reality is that we need a large number of the population to be immune before that can happen, and that can only occur in one of two ways.

About Myles Power (757 Articles)

4 Comments on The Pfizer COVID-19 Vaccination explained

  1. Thanks for the clear explanation Myles. What is the oily substance used to “bubble wrap” the mRNA?


  2. The main thing that keeps me skeptical here is the lack of rejected Phase 3 vaccines – which considering typical rates that medications fail Phase 3 standards, is abnormal. I’m not even assuming that anyone is lying, or anything nefarious. I just think that typical standards for this kind of thing have been relaxed, and that the disincentive for going against the grain here is just too great – at best, they would be seen as an unreasonable pessimist, and at worse, be labeled an anti-vaxer until the end of their natural life.


  3. Simple thank you to you.
    And much respect.
    Stay safe and scientific in 2021.


  4. Still it is unteated amd unproven


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