I had assumed that the lower vaccine take-up in London was largely due to it having a younger population. Whereas that's true to an extent, a significant portion of older people aren't vaccinated either...
For instance. East Suffolk has 96% of its 70-74 year olds double-vaccinated, Lambeth has just 74%. With the Delta variant, surely things risk getting really bad in inner London boroughs as and when restrictions are lifted completely as they struggle to get to 60% full vaccinated adults overall - below here immunity levels - whilst other parts of the country end up in excess of 90%.