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Focosi, D.

Publications and source records attributed to Focosi, D..

2 recordsLinked to original sources

Convergent evolution in SARS-CoV-2 Spike creates a variant soup that causes new COVID-19 waves.

The first 2 years of the COVID-19 pandemic were mainly characterized by convergent evolution of mutations of SARS-CoV-2 Spike protein at residues K417, L452, E484, N501 and P681 across different variants of concern (Alpha, Beta, Gamma, and Delta). Since Spring 2022 and the third year of the pandemic, with the advent of Omicron and its sublineages, convergent evolution has led to the observation of different lineages acquiring an additional group of mutations at different amino acid residues, namely R346, K444, N450, N460, F486, F490, Q493, and S494. Mutations at these residues have become increasingly prevalent during Summer and Autumn 2022, with combinations showing increased fitness. The most likely reason for this convergence is the selective pressure exerted by previous infection- or vaccine-elicited immunity. Such accelerated evolution has caused failure of all anti-Spike monoclonal antibodies, including bebtelovimab and cilgavimab. While we are learning how fast coronaviruses can mutate and recombine, we should reconsider opportunities for economically sustainable escape-proof combination therapies, and refocus antibody-mediated therapeutic efforts on polyclonal preparations that are less likely to allow for viral immune escape.

microbiology↗

Plasma after both SARS-CoV-2 boosted vaccination and COVID-19 potently neutralizes BQ1.1 and XBB.

ObjectivesRecent 2022 SARS-CoV-2 Omicron variants, have acquired resistance to most neutralizing anti-Spike monoclonal antibodies authorized, and the BQ.1.* sublineages are notably resistant to all authorized monoclonal antibodies. Polyclonal antibodies from individuals both vaccinated and recently recovered from Omicron COVID-19 (VaxCCP) could retain new Omicron neutralizing activity. MethodsHere we reviewed BQ.1.* virus neutralization data from 920 individual patient samples from 43 separate cohorts defined by boosted vaccinations with or without recent Omicron COVID-19, as well as infection without vaccination. ResultsMore than 90% of the plasma samples from individuals in the recently (within 6 months) boosted VaxCCP study cohorts neutralized BQ.1.1, and BF.7 with 100% neutralization of WA-1, BA.4/5, BA.4.6 and BA.2.75. The geometric mean of the geometric mean 50% neutralizing titers (GM (GMT50) were 314, 78 and 204 for BQ.1.1, XBB.1 and BF.7, respectively. Compared to VaxCCP, plasma sampled from COVID-19 naive subjects who also recently within 6 months received at least a third vaccine dose had about half of the GM (GMT50) for all viral variants. ConclusionsBoosted VaxCCP characterized by either recent vaccine dose or infection event within 6 months represents a robust, variant-resilient, passive immunotherapy against the new Omicron BQ.1.1, XBB.1 and BF.7 variants.

microbiology↗