The United Kingdom reported a new variant, termed VUI 202012/01 (Variant Under Investigation, year 2020, month 12, variant 01). It was defined by multiple spike protein changes (deletion 69-70, deletion 145, N501Y, A570D, D614G, P681H, T716I, S982A, D1118H). An increasing fraction in Southern England (all from clade GR) share several of these changes and a handful have been seen through imports in other countries. Based on evaluation of effect on virus structure and function, the most relevant might be N501Y (orange in Figure; host receptor and antibody binding, also reported at gisaid.org/spike) and the deletions (cyan in Figure) in positions contributing to potential spike surface variation (Y145del is where some antibodies like neutralizing 4A8 bind).
The other mutations (blue in Figure) are further down the structure and their effect is less clear. There is also an early NS8 Q27stop codon in these strains which could be relevant as ORF8 deletions have been seen before for this virus (including in Singapore, notably resulting in attenuation). As seen on many occasions before, changes are naturally expected for viruses and are most often simply neutral regional markers useful for contact tracing. The changes seen have rarely been affecting viral fitness and almost never affect clinical outcome but the detailed effects of these changes remain to be determined fully.
Combining multiple data and reports, the UK NERVTAG group of experts concluded 'In summary, NERVTAG has moderate confidence that VUI-202012/01 demonstrates a substantial increase in transmissibility compared to other variants' (NERVTAG: Investigation of novel SARS-CoV-2 variant: 202012/01)