International Movement

The stem branch separating G.1 from its closest Togo relative implies divergence from A.2.2 about 18 months earlier. The precise geographic origin of G.1 remains unresolved. The study found evidence of export from Sierra Leone to the United States, Germany, and Guinea. Sierra Leone G.1 and United States A.2.2 viruses likely descend from Nigerian clade IIb/sh2017 A.2.2, but an intermediate source cannot be excluded. G.1 is nested within A.2.2, which is mostly represented in public data by United States sequences. United States A.2.2 genomes likely represented independent imports from Nigerian A.2.2 rather than cryptic diversification in the United States.