UK was a proponent of one dose for many months, then they got second doses a lot further apart. In the USA they were always pushing Phiefer and Monderna as timed 2nd doses with 3 or 4 weeks apart. I live in a area of 78% of couple of million close by have both doses. Now in Texas recently they had a sample of some 600 individual being asymptomatic from a large sampling of positives instances of fully vaccinated people, only 8 people with underlining conditions died in hospitals. That how effective its been to be fully vaccinated with the latest India based delta variation. So in the end the UK to USA comparison is erroneous for you to use as a argument. But keep up the argument.