Rapid Emergence and Spread of Severe Acute Respiratory Syndrome Coronavirus 2 Gamma (P.1) Variant in Haiti

Abstract

After an initial wave of coronavirus disease 2019 (COVID-19) in Haiti in summer 2020 (primarily lineage B.1), seropositivity for anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunoglobulin G (IgG) was ~40%. Variant P.1 (gamma) was introduced in February 2021, with an initially limited introduction followed by exponential local dissemination within this unvaccinated population with prior exposure to earlier SARS-CoV-2 lineages.

Figure 1.

Distribution of Haitian SARS-CoV-2 lineages, reported cases and deaths over time, and phylogeography of SARS-CoV-2 in Haiti. A, Counts of reported cases (×10) and deaths by WHO (https://covid19.who.int/) are shown in blue and red, respectively. B, Distribution of SARS-CoV-2 pango-lineages circulating in Haiti through time and colored according to the legend. Other lineages are defined as present within < 2% of the total sample population. C, Maximum likelihood ancestral state reconstruction of the origin of the COVID-19 epidemic in Haiti performed with TreeTime using genomes from Haiti and other countries linked to Haiti sequences via genetic similarity. Branch lengths are scaled in time by molecular clock calibration and colored according to origin as in the legend. Dots at nodes are colored based on the ancestry; dots circled in black or red indicate ≥ 90% or ≥ 70% (only the case of P.1 Haitian clade) statistical bootstrap support for the clade. B.1 and P.1 Haitian clades are shown. COVID-19, coronavirus disease 2019; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2; WHO, World Health Organization.