Emergent Omicron BR.2.1 sublineage of SARS-CoV-2 in New South Wales, Australia: a subvariant with high fitness but without increased disease severity

Autor: Annaleise R Howard-Jones, Alicia Arnott, Jenny Draper, Mailie Gall, Sally Ellis, Kelsi Marris, Christine Selvey, Kerri Basile, Dominic E Dwyer, Vitali Sintchenko, Jen Kok
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: International Journal of Infectious Diseases, Vol 130, Iss , Pp 38-41 (2023)
Druh dokumentu: article
ISSN: 1201-9712
DOI: 10.1016/j.ijid.2023.02.019
Popis: Objectives: To describe the epidemiology and impact of Omicron BR.2.1, an emergent SARS-CoV-2 Omicron BA.2.75 sublineage displaying high fitness compared to other cocirculating subvariants in New South Wales, Australia. Methods: From September 01 to November 26, 2022, 4971 SARS-CoV-2 consensus genomes from unique patients were generated, and correlated with international travel and reinfection history, and admission to the intensive care unit. Results: BR.2.1 became the predominant variant by late November, and was responsible for a significantly higher proportion of community-acquired cases during the study period (55.1% vs 38.4%, P < 0.001). Reinfections (defined as occurring between 6 and 24 weeks after a prior diagnosis of COVID-19) were significantly higher among BR.2.1 compared to non-BR.2.1 infected persons (17.0% vs 6.0%, P < 0.001). BR.2.1 cases were also significantly younger compared to non-BR.2.1 (median age 48 years (interquartile range [IQR] 32) vs 53 years (IQR 32), P = 0.004). The proportion of patients admitted to the intensive care unit with BR.2.1 was not significantly higher than other subvariants (2.3% vs 2.0%, P = 0.717). Conclusion: Having emerged locally within New South Wales, BR.2.1 caused a significant number of SARS-CoV-2 reinfections, but with disease severity comparable with other currently circulating lineages. Given its rapid rise in prevalence, BR.2.1 has the potential to become established internationally.
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