has part has part has_part derives from has average R0 D614G in SARS-CoV-2 S protein SARS-CoV-2 Delta variant 5.02 Nextstrain clade 21A https://nextstrain.org/ncov/gisaid/global Anthony Huffman, Yongqun "Oliver" He SARS-CoV-2 B.1.617.2 virus SARS-CoV-2 based on WHO classification SARS-CoV-2 Severe acute respiratory syndrome coronavirus 2 severe acute respiratory syndrome coronavirus 2