New SARS-CoV-2 variants are continually emerging and have the potential to present challenges to public health responses worldwide. This report discusses the early detection of the lineage JN.2.5 (alias of B.1.1.529.2.86.1.2.5) in Rio de Janeiro, Brazil. The variant was identified in early 2024 through viral whole-genome sequencing and phylogenetic analysis, revealing that circulating strains present genetic similarities to sequences reported in Canada, Poland, Belgium, and England. While the circulation of diverse Omicron sub lineages has significantly impacted COVID-19 epidemiology in Brazil, the consequences of the circulation of the novel variant are uncertain. Considering its immunological escape capabilities and epidemiological behavior observed elsewhere, close monitoring of this variant epidemiology is recommended.

The authors have declared no competing interest.

https://doi.org/10.55876/gis8.240311rg

This work was supported in part by grants from Fundacao Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro/FAPERJ (E−26/210.785/2021) and from Instituto Todos pela Saude/ITpS (C1114/2021). These sponsors had no role in the study design, execution, analysis, interpretation of data, or decision to present the results.

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The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

The study was conducted according to the guidelines of the Declaration of Helsinki, and approved by the Ethics Committee of Hospital Universitário Clementino Fraga Filho (protocol numbers 30161620.0.1001.5257).

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All generated genome sequences have been deposited on GISAID EpiCoV (EPI_SET_240311rg)