tetano
Editor, Senior Moderator
Why do we have perfectly good vaccines against some diseases like measles and not others? Why do vaccines against diseases like influenza require constant updating while others have remained the same for decades?
I like to give the answer using what I call my "wardrobe" analogy. The immune system does not usually perceive a pathogen in its entirety but rather by its parts. If we imagine that these parts constitute their garments, and that these garments can vary in colour, then the "wardrobe" of a pathogen can either be extremely colourful or completely monochromatic depending on the degree of structural and functional variation that is permitted within the parts presented to the immune system. Some pathogens (like measles) have a very monochromatic wardrobe, meaning that the parts presented to the immune system (which I shall henceforward refer to as 'epitopes') are not capable of any significant variation. As a result, when we become infected with measles, we develop a lifelong ability to recognise the virus after we recover. By contrast, influenza has a diverse wardrobe which enables it to reinfect us simply by reaching into its wardrobe and donning a new hat and jacket and taking up the hem of its skirt.
...
https://naturemicrobiologycommunity...mathematical-model-to-a-new-influenza-vaccine
I like to give the answer using what I call my "wardrobe" analogy. The immune system does not usually perceive a pathogen in its entirety but rather by its parts. If we imagine that these parts constitute their garments, and that these garments can vary in colour, then the "wardrobe" of a pathogen can either be extremely colourful or completely monochromatic depending on the degree of structural and functional variation that is permitted within the parts presented to the immune system. Some pathogens (like measles) have a very monochromatic wardrobe, meaning that the parts presented to the immune system (which I shall henceforward refer to as 'epitopes') are not capable of any significant variation. As a result, when we become infected with measles, we develop a lifelong ability to recognise the virus after we recover. By contrast, influenza has a diverse wardrobe which enables it to reinfect us simply by reaching into its wardrobe and donning a new hat and jacket and taking up the hem of its skirt.
...
https://naturemicrobiologycommunity...mathematical-model-to-a-new-influenza-vaccine