Improved precursor-fused novel coronavirus S protein mutant as well as nucleic acid molecule, vector, cell and application of improved precursor-fused novel coronavirus S protein mutant

The invention relates to the field of biological medicine, and discloses an improved novel coronavirus S protein mutant fused with a precursor as well as a nucleic acid molecule, a carrier, a cell and application thereof. Compared with wild type SARS-CoV-2 virus S protein, the S protein mutant disclosed by the invention contains one or more amino acid mutations or cleavage. The S protein mutant provided by the invention can form a trimer structure and maintain the trimer structure in a fusion precursor state; meanwhile, when mammalian cells are used for expressing target protein, the yield is greatly increased, the generated protein is more stable and uniform, the immunogenicity is high when the protein is used as a vaccine or a vaccine component, immunized animals can be induced to generate high related antibodies, and the immunogenicity is high. The novel coronavirus strains which effectively inhibit wild type, alpha type, delta type and lambda type have the characteristics of high efficiency, broad spectru