Both places are reporting new strains. In the UK, the PM has reported that there is a new strain that is significantly more infectious while not necessarily more fatal. In response, the greater London area is locking down again, and restrictions that were to be relaxed for Christmas in the UK will no longer be. South African researchers say that their new strain *seems* to be more significantly affecting younger people with severe illness that did not have co-morbidities, without being necessarily more infectious.

UK: London Put in Emergency Lockdown as U.K. Fights New Strain (msn.com)

South Africa: COVID-19: South Africa identifies new coronavirus variant causing surge in infections (msn.com)

Hopefully this turns out to be a non-event like the Denmark/Mink thing. But if not, you heard it here first, folks.