Identification of an immunodominant neutralizing epitope of porcine astrovirus type 5 capsid protein

• A neutralizing monoclonal antibody against the capsid protein of PAstV5 was prepared for the first time. • The B cell epitope of PAstV5 capsid protein was identified for the first time. • The monoclonal antibody 6c6 had strong neutralizing activity against PAstV5. • The identified epitope formed an alpha spiral structure and located outside the three-dimensional structure of the protein.