Abstract
In late July, 2023, SARS-CoV-2 surveillance programmes identified a new, highly mutated omicron subvariant, BA.2.86.1 Initial estimates place the effective reproduction number of BA.2.86 at 1·29-times greater than that of XBB.1.5 and near equivalent to that of EG.5.1, one of the most rapidly expanding XBB subvariants.2 Since the emergence of BA.2.86, multiple countries have reported its presence, including an outbreak in a British care home, with an attack rate above 85%, where the majority of infected residents had received a SARS-CoV-2 Beta variant-based subunit vaccine 4 months earlier.3 Relative to the SARS-CoV-2 index strain, the BA.2.86 spike protein has 60 amino acid changes, located predominantly in the N-terminal and receptor binding domains (figure A). [...]this study addresses the paucity of BA.2.86 and EG.5.1 virus characterisation data on clinical isolates, which represent the pathogens circulating among individuals. PJ is the science officer of the European Society of Clinical Microbiology and Infectious Diseases Study Group in Public Health Microbiology, and a member of the European Society of Clinical Microbiology and Infectious Diseases Emerging Infections Task Force.