We report a rapidly growing lineage in the UK associated with an unexpectedly large number of genetic changes | There is a discussion here on the nature of the new virus

THIS IS WHAT IS GOING ON:

There is a discussion here on the nature of the new virus [link to virological.org (secure)]

Preliminary genomic characterisation of an emergent SARS-CoV-2 lineage in the UK defined by a novel set of spike mutations

Several aspects of this cluster are noteworthy for epidemiological and biological reasons and we report preliminary findings below. In summary:

The B.1.1.7 lineage accounts for an increasing proportion of cases in parts of England. The number of B.1.1.7 cases, and the number of regions reporting B.1.1.7 infections, are growing.
B.1.1.7 has an unusually large number of genetic changes, particularly in the spike protein.

See the chart of the B.1.1.7 virus in the linked page and notice how different it is from the previous strain the vaccine has been developed for.

They conclude:

We report a rapidly growing lineage in the UK associated with an unexpectedly large number of genetic changes including in the receptor-binding domain and associated with the furin cleavage site. Given (i) the experimentally-predicted and plausible phenotypic consequences of some of these mutations, (ii) their unknown effects when present in combination, and (iii) the high growth rate of B.1.1.7 in the UK, this novel lineage requires urgent laboratory characterisation and enhanced genomic surveillance worldwide.