They've got these "jab vans" in my part of London that drive around and pitch up in random spots, like a park or a market or next to a row of shops. These 20-year-olds in bright blue shirts then proceed to ask passers-by: "Have you had all of your covid vaccines?" And they point to a dingy tent with a foldout chair and some bored-looking guy around the same age wearing an unbuttoned lab coat.