London: Scientific experts have warned of a second wave of the coronavirus pandemic and another complete nation-wide lockdown in the UK unless stricter measures are adhered to amid a rising number of infections in the country over the past week.Peter Openshaw, a professor of experimental medicine and an expert respiratory medicine at Imperial College London, said the new “rule of six" restrictions on large gatherings which comes in force from Monday is extremely crucial."I think everyone is in agreement that we really need to act very quickly now in order to prevent this from growing exponentially and that's the main point, is that we must act fast because it is so much harder to get this sort of thing under control if you delay even a few.