Biology is very fascinating and we humans are just starting to comprehend it.
What are mRNA vaccines?
In order to know what mRNA vaccines are, we first need to know about proteins, or even, what are we humans made of?
Proteins build any cell in your body, therefore, your cells are protein factories that communicate by transferring proteins or electric signals from one cell to another, to keep you optimally healthy. This production of proteins is called protein synthesis.
DNA contains the information to built the proteins, but cells can not produce proteins using DNA. Because DNA is perfect to storage information and RNA is better for producing them easily and faster..
Image (1): The Dogma
Protein synthesis, the central dogma of molecular biology, explains how cells required instructions to build proteins to repair themselves, make them work If a condition is present or not. Like when they detect a foreign protein, or, even a protein that is produced incorrectly in other cells. We called this the immune system. (Ref. Image 1)
Basically your body is mixed of proteins working together to keep you alive. On the other hand, pathogens like viruses are also made of proteins.
Image (2): You and the SARS CoV-2
As you could noticed proteins in your body have multiple functions depending on which system they are found. Like, defense, support, storage, structure, transport, digestion, etc. (Ref. Image 2)
Did you know that antibodies are proteins that destroy pathogens? Like SARS CoV-2.
So, What are mRNA vaccines?
mRNA vaccines use the central dogma of microbiology to manufacture a piece, (a protein) of the pathogen for your body.
Image (3): The mRNA Vaccine
Now that we understand the basics, we can define an mRNA vaccine as a method to produce an immune response by creating an external protein, (“a non-self” antigen), from a pathogen inside our bodies. Here your body produces antibodies to eliminate, and memory B cells to remember the spike proteins. Acting as a simulation to quickly reduce the number of pathogen units in a real infection.
What do ingredients of the mRNA vaccines do to my body?
The mRNA vaccines BioNTech/Pfizer (Comirnaty) and Moderna (SpikeVax) have been approved by Canada to help us to fight COVID-19.
mRNA COVID-19 vaccines are made of tree main parts. A message, a delivery and a quality control system.
Let’s start with the (Messenger RNA) mRNA. This contains the genetic information to create an antigen, which, in this case is the (S) protein, or also known as Spike protein. Overall, mRNA is very fragile on its own, and your body has evolved mechanisms that detect abnormal and external mRNA. For these reasons, it can not survive in your body for so long without protection. Without this protection the mRNA can not create the (S) protein to show your immune system what SARS CoV-2 looks like. But, we will come back to the spike protein topic later.
So, scientists need something to protect and deliver safely this vital message. Here, enters the Solid Lipid Nanoparticles (SLPs) containing the mRNA instructions. Just as a fancy resistant glass bottle with a very fragile note on a piece of paper, in the middle of the ocean. So, these SLPs enter to the cytoplasm of your muscle cells just moments after being vaccinated. They help the mRNA to access to your cells because they contain biochemical keys that allow it. Once the inside the mRNAs meet your ribosomes which create the Spike proteins. This process naturally occurs in your body every single time, and it is called translation.
In order to work efficiently, SLPs required a specific biochemistry to be stable long enough to deliver the mRNA message. This is achieved with the help of glucose, salts, such as, potassium chloride, sodium chloride, or dibasic sodium phosphate dihydrate and others. Sounds scary isn’t it? But, what If I told you have been using sodium chloride (table salt) most of your life? Or, prob that you haven’t drunk enough Dihydrogen monoxide (water) today haha. Potassium chloride is used as a table salt substitute but also to treat low potassium levels in patients.
On the scary acid list, we found acids such as Acetic Acid (found is large quantities in vinegar), or Tromethamine & Tromethamine hydrochloride, these are used to treat metabolic acidosis, or highly acidic blood. Many others ingredients of these ingredients with the exception of glucose (sugar) do not have common names, therefore, their scientific names are used. These also helps scientists to identify exactly the formula used, worldwide.
Making mRNA vaccines work might sound easy nowadays, but 30 years ago the first mRNA vaccines did not have this modern SLPs. Therefore, it was impossible to keep the mRNA long enough to produce the desire proteins.
Did you know that?
If mRNAs were able to stay longer than usual this wouldn’t be possible. Your body has evolved mechanisms that recognize rogue mRNAs in your body. Such as, the Nonsense-mediated mRNA decay (NMD) pathway. Acting as a quality control system for deleting aberrant host mRNAs, but also playing a role as an innate host defense army against cytoplasmic RNA viruses. Like herpesviruses and adenoviruses.
