I am genuinely intrigued. How does this fast tracking system for BA and VS passengers that are fully vaccinated not make the UK Border Agency complicit with not treating all passengers, from all airlines equally which surely ought to be one of the fundamental rules for any border agency. If The fast tracking system was available to all carriers, should they wish to participate, that would be fine and dandy, but that isn't what the article implies.
If I were Air China, or say, United, I would be mightily miffed.
https://www.bbc.co.uk/news/business-57743038