About 70% of the confirmed cases of CCP-virus are linked to a strain with D614G mutation, showing significantly more infective.
See D614G in a 3-D model:
In this video, the D614G mutation in the SARS-CoV-2 Spike protein is explored, which is thought to play a key role for higher viral transmissibility.
This is based on a research paper:
“Spike mutation pipeline reveals the emergence of a more transmissible form of SARS-CoV-2” – (Pre-print) Korber et al (2020).