The student numbers part-explain the surge in Manchester, Leeds etc and it's amongst a group who are less likely to spread it than others. Awkward if you're in the middle of it but one big cluster has less opportunity for general growth into the wider population than through lots of little clusters.
University cities in the US and other countries seem to have got through this so I expect we will too. if we didn't have testing, we'd probably not have been aware of this - is it a sign that we are beginning to get a handle on this?
The government is talking about mass testing and moving to point of care tests. I am sure a lot of people are working on it. I hope that just when this becomes a possibility a vaccine will start to be rolled out.
This is a bit speculative...there is more to immunity than antibodies. Many have an immune response to Sars-Cov-2 through past exposure to coronaviruses and this may part explain it's patchy geographical distribution. This implies it's not that clear cut i.e. 100 -8 %. There are memory B cells and T cell responses to infection, hence the decline in antibodies after infection is not necessarily a problem.
The only way out of this epidemic was through immunity but no one found a way of infecting the herd safely without the death of a lot of vulnerable people because the human population can not be completely isolated. It might have been possible if we could screen i.e. test people a lot more efficiently. Fortunately it looks like immunity will come from vaccines so the policy of herd immunity died when it became clear that vaccines were the way out.
I posted a link a while back about the B/T cells memory and I do think this is missing (or has been neglected) from much of the reporting.