Evolution, virulence and immunogenicity of relevant SARS-CoV-2 spike mutants

SeqCOVm-SPAIN consortium.Trabajo presentado al 31st European Congress of Clinical Microbiology and Infectious Diseases (ECCMID), celebrado online del 9 al 12 de julio de 2021.We have detected two mutations in the Spike protein of SARS-CoV-2 sequences at amino acid positions 1163 and 1167 which appeared independently in multiple transmission clusters and different genetic backgrounds, indicating they may increase viral fitness. Both mutations appeared together in a cluster within clade 20E. This cluster is characterized by 12 additional single nucleotide polymorphisms but no deletions. The available structural information of the S protein in the preand post-fusion conformations we predict that both mutations confer rigidity, that potentially could decrease viral fitness. Despite the multiple and successful appearance of two HR2 mutations during the first year of SARS-CoV-2 evolution, in vi tro stability, infectivi ty, or antibody escape does not seem to play a role.This work was funded by the Instituto de Salud Carlos III project COV2o/o0140 and COV2o/o0437• Spanish National Research Council project CSIC"COV19~021 and CSIC-COVID19-082, and the Generalitat Valenciana (SEJI/2019/011 and Covid 19-SCI).Action co-financed by the European Union through the Operational Program of the European Regional Development Fund (ERDF) ofthe Valencian Community 2014-2020. MC is supported by Ramón y Caja/program from Ministerio de Ciencia, grant RTI2018-094399-A-Joo.Peer reviewe