Abstract: The present disclosure belongs to the technical field of virus immunoassay and provides a broad-spectrum peptide antigen of SARS-CoV-2, a specific neutralizing antibody and use thereof. A broad-spectrum peptide antigen of SARS-CoV-2, with an amino acid sequence set forth in SEQ ID NO: 1, reacts with human SARS-CoV-2 positive serum, and can specifically bind to a novel coronavirus antibody. Based on the peptide sequence of the present disclosure, a fusion protein with broad-spectrum triple tandem peptides of SARS-CoV-2 is prepared using PCR, prokaryotic expression and protein purification technology to simulate the trimeric mode of SARS-CoV-2 S protein in its natural state. The fusion protein is used as an antigen to immunize mice, and can produce a specific anti-SARS-CoV-2 neutralizing antibody. The neutralizing antibody may be promising in anti-infective treatment, vaccine development and detection kit development for SARS-CoV-2.

Abstract: Disclosed is an antigen peptide with an infectious bronchitis virus (IBV)-specific neutralizing epitope, in which the peptide is a cyclic polypeptide, and the amino acid sequence of the peptide is CSCPYVSYGRFCIQPDGSIKQC. Also disclosed are an IBV specific antibody and a preparation method thereof. Further disclosed is an ELISA method as an alternative to the neutralization potency assay. The disclosure also discloses an ELISA detection kit, and using the established pELISA method to detect IBV antibodies, it is found that the method is positively correlated with anti-IBV neutralizing antibodies, which may be used to evaluate the immune effect of IBV vaccines on IBV infected chickens and to determine the antibody level, thereby benefiting the health management of chicken flocks.

Abstract: The present disclosure provides a recombinant herpesvirus of turkeys (HVT) and a preparation method and use thereof. The present disclosure specifically provides a recombinant HVT, where an exogenous gene is inserted in a spacer region between an HVT005 region and an HVT006 region of an HVT genome; and the exogenous gene is selected from a gene derived from the group consisting of a Newcastle disease virus (NDV), an avian influenza virus (AIV), and an infectious bursal disease virus (IBDV); the spacer region between an HVT005 region and an HVT006 region of an HVT genome is located between 8,867 nt and 9,319 nt of the HVT genome, and has a nucleotide sequence set forth in SEQ ID NO: 1.