The 18 variations are like a deck of 18 cards, the virus 'shuffles' one into use, next year another works better. The multivalent vaccine is for all 18 cards, e

The 18 variations are like a deck of 18 cards, the virus 'shuffles' one into use, next year another works better. The multivalent vaccine is for all 18 cards, evolutionary escape is far less likely, if not impossible.