The following videos are most excellent – but, if you have not ever been exposed to the language of ‘immunology’ or the latest theories in this branch of science, you may find the following few explanations useful. Otherwise, please, proceed to the videos themselves!
Our body is made up of cells.
The outer layer of the cell is called a cell membrane. It is made up of a waterproof ‘double-layer’ of ‘phospholipid bilayer’ – which make it very difficult for either water or fat-based substances to make it into the cell. (A phospholipid is a thigie that is water-soluble on one end, fat-soluble on the other. When they form a bilayer (a two-layer), they line up in just such a way that neither water nor fat soluble stuff can enter the cell through – which is why they are so useful in forming the cell wall.)
But, in order to live, the cell needs to exchange chemicals (like food and oxygen) with the outside. In order to do this, each cell has some proteins built into the cell wall. These proteins form channels that permit specific chemical reactions to occur – thus permitting the cell to ‘eat’ and ‘breathe’.
These proteins are not ‘flush’ with the rest of the cell wall – they form very specific ‘bumps’ on the surface of the cell wall that are unique to each protein…and each cell has a unique pattern of these proteins.
Thus, each different type of cell has a ‘fingerprint’ pattern of protein ‘bumps’ in the cell wall – that is how the body recognizes each cell for what it is and what function it performs.
Virus cells also have a unique ‘fingerprint’ pattern of proteins in their cell walls – and it is by this ‘fingerprint’ that our immune system learns to recognize them. It then builds specific anti-bodies that check for this specific ‘fingerprint’ on the virus wall and if they detect it, they bind to it and eventually kill it.
Viruses are notorious for changing their ‘surface proteins’ and thus their ‘fingerprints’, making it impossible for our immune systems to identify the virus cells and mark them for destruction.
But, even if you are not educated in this field, the conclusion in the second video will make sense!