ABSTRACT
Prominent genomic recombination has been observed between the Delta and Alpha variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), isolated from clinical specimens in Japan. Interestingly, the recombination variant detected in this study carries a spike protein identical to that in the domestic Delta variant, thereby suggesting that further risks would not be associated with infectivity and immune escape. The recombinant was classified as an XC lineage in the PANGOLIN database. It is necessary to intensively study such marked genetic variations and characterize emerging variants after careful verification of their lineage and clade assignment.
Subject(s)
COVID-19 , SARS-CoV-2 , Humans , Japan , Recombination, Genetic , SARS-CoV-2/geneticsSubject(s)
COVID-19 , Quarantine , Airports , COVID-19/prevention & control , Humans , Japan , Nepal/epidemiology , Recombination, Genetic , SARS-CoV-2/geneticsABSTRACT
In November 2021, the World Health Organization designated a new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant of concern, Omicron (PANGO lineage B.1.1.529). We report on the first 2 cases of breakthrough coronavirus disease 2019 (COVID-19) caused by Omicron in Japan among international travelers returning from the country with undetected infection. The spread of infection by Omicron were considered.