Coronavirus Disease 2019 Lineages in a Minimally Vaccinated Island Population: Genomic Epidemiology of Severe Acute Respiratory Syndrome Coronavirus 2 in Haiti.

Abstract

We monitored severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants in Haiti from 2020 to 2023. Despite Haitian coronavirus disease 2019 (COVID-19) travel restrictions and in the setting of a vaccination rate of 2.7%, the timing and lineage evolution of the Haiti epidemic mirrored what was occurring in the rest of the world. Sources for importation of lineages into Haiti were the United States, the Dominican Republic, Europe, and Brazil, with exportation of lineages to the United States, the Dominican Republic, Europe, and Asia. Viral loads in patients infected by the Delta and Omicron BA.1 variants were correlated along the phylogenies, suggesting that higher viral loads have facilitated strain transmission and evolution.