//Its common sense that they wont know if the vaccines are working for a very long time past summer.//
Why won't we?
At the moment most of the over 70s have been vaccinated. By the end of this month most of the over 55s should have been vaccinated. If lockdown is lifted in the third week of March (allowing three weeks for those vaccinated on 28th February to gain immunity) and over 55s continue to contract the virus at the same rate as now, then some doubt must be cast over the efficacy of the vaccine. As I mentioned earlier, by the end of March half the population should have received the jab, including those who form 99% of those suffering the most severe symptoms. Why will it be long past the summer until we see whether vaccines are working. Unless, of course, restrictions are not eased, in which case we'll never find out and the programme of administration would have been largely a waste of effort.