I think, tc, you need to be a little less circumspect.
There is no indication that this variant is any more damaging than any other. There is also no indication that is is resistant to vaccine (and if it was, your idea to hold fire to give more time to vaccinate people would be pointless).
On top of that, despite the increase in the number of cases, there seems to be no change to the downward trend in hospital admissions and deaths. Admissions are hovering around the 100-120 a day mark where they've been for about two weeks; deaths are averaging 10 a day where they've been for a week. 19m people have been fully vaccinated and looking at the age profile this equates to most people over the age of about 55. Almost twice that number have had at least one shot and people under 40 are now being called up for their turn.
The country cannot continue to run an ultra-precautionary strategy. Almost all of the most vulnerable to the disease who wanted the vaccine have now had it, many of the less vulnerable have and those who haven't had it are either not likely to suffer severe symptoms or they don't want it. Meanwhile the fate of many businesses, particularly in the hospitality, entertainment and travel sectors, hangs by a thread. There will always be these variants and they will almost certainly be identified in the UK because we do more "sequencing" than just about all of the rest of the world put together. Boris did err in not closing our border to India swiftly enough but frankly it would have been impossible to stop the variant reaching these shores. We just have to deal with it.