Medical Case Reports

In a recent case report, Swedish scientists documented the first known transmission of a novel recombinant SARS-CoV-2 variant. The case highlights how a patient co-infected with two different strains—sublineages of XBB (HV.1) and BA.2.86.1—generated and transmitted a hybrid variant to another patient within a hospital setting. In October 2023, routine genomic surveillance in Stockholm identified a recombinant variant in a patient (Patient B). This hybrid virus combined genetic material from two distinct lineages: the 5′ part of the genome from HV.1 and the 3′ part from BA.2.86.1. The recombination occurred at the orf1b and S gene junction, producing a novel variant not observed in other Swedish patients. Meanwhile, another patient (Patient A), co-hospitalized in the same ward, was found to be co-infected with both HV.1 and BA.2.86.1. Sequencing revealed that about 30% of the virus in Patient A came from the BA.2.86.1 lineage. The two patients shared six rare mutations, confirming that