Our flu jab contains an extra ingredient for over-65s that makes it "take" better. It works against four strains of the virus. I used to get flu a lot, maybe once every couple of years, but I haven't had it since I started having the jab about ten years ago. Clearly some brilliant, er, guesswork going on there! Next stop covid booster, then next stop shingles jab. I feel like a pincushion.