Wiley MR, Fakoli L, Letizia AG, et al. - Given that Liberia has the largest reported per capita incidence of Lassa fever cases in west Africa, but with scarce genomic information on the circulating strains, researchers sought to increase the available pool of data to encourage the generation of targeted diagnostics and therapeutics. At the Liberian Institute for Biomedical Research, they processed clinical serum samples obtained from 17 positive Lassa fever cases originating from Liberia (16 cases) and Guinea (one case) within the past decade using a targeted-enrichment sequencing approach, producing 17 near-complete genomes. In addition, they generated 17 Lassa virus sequences (two from Guinea, seven from Liberia, four from Nigeria, and four from Sierra Leone) from viral stocks at the US Centers for Disease Control and Prevention (Atlanta, GA) from samples originating from the Mano River Union (Guinea, Liberia, and Sierra Leone) region and Nigeria. A comparison of sequences with existing Lassa virus genomes, and published Lassa virus assays, was performed. They identified 23 new Liberian Lassa virus genomes that were grouped within two clades (IV.A and IV.B); these were noted as genetically divergent from those circulating elsewhere in west Africa. This emphasizes the necessity to match deployed diagnostic capabilities with locally circulating strains and highlights the significance of assessing cross-lineage protection in the development of vaccines and therapeutics.