Abstract: The present disclosure provides an N protein epitope mutation marker for preparing an epitope deletion-marked vaccine strain of type II porcine reproductive and respiratory syndrome virus (PRRSV) and use thereof, belonging to the technical field of biological products. In the mutation marker, one or more amino acids are mutated based on an epitope sequence at positions 92 to 103 of a C-terminal of an N protein of the type II PRRSV; and the epitope mutation marker has an amino acid sequence shown in SEQ ID NO: 1, where X1 is selected from the group consisting of T, P, and A; and X2 is selected from the group consisting of V and A.

Abstract: The present invention relates to a method for preparing a whole bovine-derived broadly neutralizing antibody against serotype O foot-and-mouth disease virus, and belongs to the technical field of antibody preparation. The method includes the following steps: 1) conducting the immunization on the cattle; 2) screening for the serotype O foot-and-mouth disease virus antigen-specific single B cells; 3) amplifying variable region genes of the heavy and light chains; 4) acquiring constant region sequences of the heavy and light chains; 5) preparing a full-length heavy chain vector; 6) co-transfecting a cell, taking the supernatant of cell culture, and purifying. The method utilizes different foot-and-mouth disease virus strains to infect cattle and obtains a neutralizing antibody capable of neutralizing three topotypes of serotype O FMDVs by screening, and thus can obtain a whole bovine-derived broadly neutralizing monoclonal antibody.

Abstract: The present invention relates to a method for preparing a whole bovine-derived broadly neutralizing antibody against serotype O foot-and-mouth disease virus, and belongs to the technical field of antibody preparation.