Introduction and community transmission of SARS-CoV-2 lineage A.2.5 in Florida with novel spike INDELS

SARS-CoV-2 (SC2) variants of concern (VOC) continue to emerge and spread globally, threatening the use of monoclonal antibody therapies and vaccine effectiveness. Several mutations in the SC2 spike glycoprotein have been associated with reduction in antibody neutralization. Genomic surveillance of SC2 variants has been imperative to inform the public health response regarding the use of clinical therapies in specific jurisdictions based on the proportion of particular variants (e.g., Gamma (P.1)) in a region. Florida Department of Health Bureau of Public Health Laboratories (BPHL) performs tiled-amplicon whole genome sequencing for baseline and targeted surveillance of SC2 isolates in Florida from clinical specimens collected from county health departments and hospitals throughout the state. Here, we describe the introduction of SC2 lineage A.2.5 in Florida, which contains S:L452R (a substitution of therapeutic concern) and two novel Spike INDELS, the deletion of 141-143 and ins215AGY, with unknown implications on immune response. The A.2.5 lineage was first detected in Florida among an outbreak at a healthcare facility in January 2021, and subsequent A.2.5 isolates were detected across all geographical regions throughout the state. A time-scaled maximum clade credibility phylogeny determined there were at least eight separate introductions of A.2.5 in the state. The time of introduction of a monophyletic Florida clade was established to be December 2020. The Spike INDELS were determined to reside in the N-terminal domain, a region associated with antibody neutralization. As community transmission of SARS-CoV-2 in Florida continues, genomic surveillance of circulating variants in Florida and the detection of emerging variants are critical for informing public health response to COVID-19.