Rapid emergence and spread of SARS-CoV-2 gamma (P.1) variant in Haiti.

After an initial wave of COVID-19 in Haiti in summer 2020 (primarily lineage B.1), seropositivity for anti-SARS-CoV-2 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.