SARS-CoV-2 evolution in the Omicron era.

Since SARS-CoV-2 BA.5 (Omicron) emerged and spread in 2022, Omicron lineages have markedly diversified. Here we review the evolutionary trajectories and processes that underpin the emergence of these lineages, and identify the most prevalent sublineages. We discuss the potential origins of second-generation BA.2 lineages. Simple and complex recombination, antigenic drift and convergent evolution have enabled SARS-CoV-2 to accumulate mutations that alter its antigenicity. We also discuss the potential evolutionary trajectories of SARS-CoV-2 in the future.

Rise of the BQ.1.1.37 SARS-CoV-2 Sublineage, Italy.

BQ.1.1 has dominated the Europe and Americas COVID-19 wave across the 2022-2023 winter, and further viral evolution is expected to escape the consolidating immune responses. We report here the emergence of the BQ.1.1.37 variant in Italy, peaking in January 2022 before suffering competition by XBB.1.*. We attempted to correlate the potential fitness of BQ.1.1.37 with a unique two-amino acid insertion within the Spike protein.

The Era of the FLips: How Spike Mutations L455F and F456L (and A475V) Are Shaping SARS-CoV-2 Evolution.

Convergent evolution of the SARS-CoV-2 Spike protein has been mostly driven by immune escape, in particular by escape to the viral infection-neutralizing antibodies (nAbs) elicited by previous infections and/or vaccinations [...].