As the patients we treat are those at highest risk of serious health issues, and even death, from the COVID-19 virus, we thought we would take this opportunity to explain how the COVID-19 mRNA vaccine works in simple terms, to hopefully allay some fears.
The human immune system is magnificent. Its job is to recognise and attack anything that enters the body which it doesn’t recognise.If it sees a foreign protein, virus or bacteria that it doesn’t recognise, it gets ready to go into attack mode. This may take a few days, but your clever immune system will soon ramp up production of the weapons it needs to fight off whatever it sees as a danger to you.
The brilliant thing about our immune system is that once it has done this, memory immune cells remember the threat and can ramp up a defence, much more quickly, the next time round. This is particularly important when the danger may cause serious health effects or death. Clever isn’t it!
Now to understand the COVID-19 mRNA vaccine, you need to understand a little about your body’s cells and DNA. Inside your body’s 30 trillion cells is your DNA. DNA contains the blueprint for making the 100.000’s of proteins needed by your body to function. Because DNA is inside the cell, but proteins are made outside the cell, a messenger is needed to send the instructions across the cell membrane.
To do this the cell makes a copy of the instructions for just the little bit of DNA which is needed to make that particular protein. This little copy is called messenger RNA (mRNA). mRNA is then transported to the outside of the cell and uses the instructions to happily go about making the protein as directed. Once the protein is made mRNA is broken down in a few hours to days.
Virus cells, like human cells also contain DNA, mRNA and proteins. When developing a vaccine for the COVID-19 virus, scientists saw a protein on the surface of the virus (called a spike protein). The virus uses this protein to enter your cells, making it more infectious.
Scientist coded the entire DNA sequence of the virus and they found the small part of the DNA which is used by the virus to make the spike protein. From this, scientists made a copy of this small bit of DNA (mRNA) in the laboratory; which is, in simple terms, is the vaccine.
When administered, the vaccine containing the mRNA has the instructions to make the spike protein. Once mRNA starts to make the spike protein, your immune system ramps up production of the weapons it needs to fight this foreign protein. Your bodies memory immune cells have now learnt how to recognise the spike protein and know exactly how to destroy it.
Congratulations, you are now immune to COVID-19! If the virus tries to enter your body, your immune system memory cells will recognise that spike protein attached to the surface of the virus and be ready to fight it off.
The vaccine contains no actual part of the virus, so you CANNOT catch COVID-19 from the vaccine.
The vaccine is not genetically modifying your DNA. mRNA is a copy of a little bit of the virus’s DNA which contains the instructions to make the spike protein. The DNA inside the cells in your body are not affected.
What happens if the virus mutates? Should the virus mutate away from using the spike protein, chances are the new virus will be less infectious as it is the spike protein which helps it to get into your body’s cells.
The technology for making the mRNA vaccine for COVID-19 has been around for some time, however there were some difficulties in making it practical. One of these is the storage requirements of the vaccine which at -70 degrees and -20 degrees makes the storage and transport of these frozen products difficult. Practical solutions for this are being rolled out.