Just look at data of percentage of people vaccinated in the western world where supply is actually available for anyone to take the vaccine right now. The US is last.
And look at the geographical distributions of low vaccine rates. Is very low in very wealthy parts of the UK where house prices are astronomical vs high dentisty pupation centers.
Why should most of London be at a higher vaccination rates than Oxford or Cambridge city centres? There is clear hesitancy here of some small groups that live near universities and make up <5% of the population. (Source ONS UK stats)
There is something specific to the US here.