Provided is a
mutant of a respiratory syncytial
virus (RSV) pre-fusion conformational
F protein. The
mutant comprises an
amino acid mutation relative to the
amino acid sequence of a wild-type RSV
F protein, the
amino acid mutation being amino acids at a position 392 and a position 493 or a position near the position 493 being substituted by C, and a
disulfide bond being formed between a position 392C and a position 493C or a position near the position 493C after the
mutation. Also provided are a related
DNA coding sequence, recombinant
plasmid and mRNA sequence and a corresponding RSV vaccine. By introducing a
disulfide bond at a suitable position, and combining same with cavity filling, electrostatic mutation,
proline mutation and the like, the expression and stability of an
F protein having pre- and post-fusion conformations and a trimerized conformation are significantly improved, and the conformation of the F
protein is significantly inhibited from being converted into the post-fusion conformation. The
mutant is also applied to preparation of an RSV vaccine and RSV
infection detection.