The present invention relates to attenuated African Swine Fever viruses. The attenuated viruses protect pigs against subsequent challenge with virulent virus. The present invention also relates to the use of such attenuated viruses to treat and/or prevent African Swine Fever. The invention also relates to EP402R proteins of African Swine Fever virus comprising particular amino acid substitutions, as well as polynucleotides encoding such proteins and African Swine Fever viruses comprising such proteins.

The present invention relates to: a recombinant vector comprising a nucleotide sequence of antigen protein(s) Lectin, CD2v, p72, p54, p30, p15, p35, E199L, and/or F317L of an African swine fever virus; a transformant transformed by means of the recombinant vector; and a vaccine composition for preventing African swine fever, comprising, as an active ingredient, African swine fever virus antigen protein(s) Lectin, CD2v, p72, p54, p30, p15, p35, E199L, and/or F317L, isolated from the transformant; and the like.

Arbovirus carries an altered furin cleavage site that results in enhanced cleavage of a precursor polyprotein, such as, prE2 or prM. Dengue virus particles can have an amino acid alteration within amino acids 80-130 of prM. Zika virus particles can have alterations at amino residues at and/or about the furin cleavage site. The virus can be produced in insect cells. The virus does not form progeny virus in mammal cells.

The present invention provides an attenuated African Swine Fever (ASF) virus which lacks a functional version of the following genes: multigene-family 360 genes 9L, 10L, 11L, 12L, 13L and 14L; and multigene-family 505 genes 1R, 2R, 3R and 4R. The invention further provides an attenuated African Swine Fever (ASF) virus which lacks a functional version of the DP148R gene. The present invention also provides a vaccine comprising such an attenuated virus and its use to prevent ASF. Further, the invention relates to intranasal administration of an attenuated ASF virus.

A recombinant vector containing the immunogenic protein of African swine fever virus, a recombinant bacterium and use thereof, and relates to the technical field of gene recombination. The recombinant vector can be used to construct a recombinant Lactobacillus expressing the immunogenic protein of African swine fever virus, and after mixing the Lactobacillus solution that can secrete protein p72 and protein p54, respectively, an oral live bacterial preparation for preventing African swine fever can be prepared. The oral live bacteria preparation prepared by the disclosure can safely, effectively and quickly prevent the infection of African swine fever virus to pigs, and does not contain an immune process.

The present invention relates to a polypeptide, a polynucleotide, a plasmid and a vaccine composition comprising the same, which are involved in eliciting immune responses to African Swine Fever. And also, it relates to a method of eliciting immune responses to African Swine Fever in a subject. In addition, it relates to a pharmaceutical composition for treating or preventing African Swine Fever comprising a polypeptide, a polynucleotide or a plasmid, which is involved in eliciting immune responses to African Swine Fever. Also, it relates to a method of treating or preventing African Swine Fever in a subject.

An african swine fever virus vaccine includes five groups of antigens in total, and each group is respectively obtained by constructing recombinant adenovirus vectors co-expressing four antigen genes of african swine fever virus, and packaged by 293TD37 cells. The four antigenic genes of African swine fever virus in each group are 1, P72, B602L, P30 and P54; 2, CP129Rubiqutin, MGF5L6L, CP312R, and MGF110-4L; 3, L8Lubiqutin, I215L, I73RHBsAgHBsAg and E146L; 4, EP402R, EP153R, I177L, and K205Rubiqutin; 5, F317L, A151R, P34, and pp62. The construction of the recombinant adenovirus vector for co-expression of four antigen genes of the african swine fever virus mainly includes: knocking out E1, E3, E2a and E4 genes of the adenovirus vector by CRISPR/cas9 technology, constructing an ORF6/7 expression frame of E4 in an E2a region, and constructing shuttle plasmids in E1 and E4 regions for appropriately expressing four antigen genes, thereby obtaining a completely new adenovirus vector.

A viral vector delivery system for both respiratory and digestive tracts of pigs and an application thereof are provided. The viral vector delivery system includes a backbone plasmid and a helper plasmid. The backbone plasmid is produced by inserting a full-length cDNA of porcine enterovirus B (PEVB) into a pUC57 plasmid. The helper plasmid is produced by inserting a green fluorescent protein-coding gene into a plasmid pCAG-T7-polymerase. The viral vector delivery system can be constructed with high efficiency, can quickly cause a cytopathic effect (CPE) after infecting cells, has a viral titer up to 10.sup.7.75 TCID.sub.50/mL, and can maintain high stability. A pathogenic epitope for the respiratory and digestive tracts of pigs is inserted into the backbone plasmid to produce a vaccine antigen, which is non-pathogenic, has high stability and a high viral titer, and allows a prominent immunization effect after being inoculated in pigs.

The present application relates to a pathogen-like antigen (PLA) complex, and a preparation method therefor and an application thereof. The PLA complex consists of structurally-modified Escherichia coli bacteriophage virus-like particles (VLPs) and antigens displayed thereon, and nucleic acids are encapsulated inside the VLPs.

The invention is directed to a recombinant nucleic acid molecule comprising an expression cassette encoding a polyepitope comprising T-cell antigens from proteins of African Swine Fever Virus. The invention further relates to a viral particle, comprising said recombinant nucleic acid molecule, and to a viral particle comprising B-cell antigens of African Swine Fever Virus. The invention further relates to methods of stimulating an immune response in a pig comprising administering the recombinant molecule of the invention, and/or the viral particle of the invention, to the pig in an amount effective to induce an immune response.