Dressed to kill: what do infectious disease agents have in their wardrobes

Abstract

Why do we have vaccines against some diseases but not against others?  To understand this, it’s useful to conceptualise an infectious agent as being in possession of their very own wardrobe, from which they are obliged to select an outfit in order to be competent at infecting and surviving within us.  What these garments represent are the fragments of the pathogen that our immune systems recognise and some pathogens like the influenza virus have a diverse wardrobe while other like measles have a very limited wardrobe.  This is why the current vaccine we have for influenza appears to require updating every few years as the virus adopts new disguises to re-infiltrate its host population, whereas a single measles vaccine can protect you for life.  But just how diverse is the wardrobe of the influenza virus?  Are we really running an endless race to catch up with its wardrobe changes?  How can we find ways to outwit it and other pathogens like the HIV virus and the malaria parasite which have extensive wardrobes at their disposal?