Provided is an application of a label gene sequence in the preparation of an H9 avian influenza vaccine strain which differentiates influenza A virus infection from vaccination, the label gene sequence containing a DNA sequence for coding an influenza B virus NA protein extracellular region amino acid sequence. Also provided are an H9 avian influenza vaccine strain which differentiates influenza A virus infection from vaccination, a preparation method therefor, and an application.

A heat-resistant H1N1 subtype influenza virus mutant strain rPR8-HA-N5 has been preserved at China Center for Type Culture Collection, Wuhan University, Wuhan, China with the preservation number of CCTCC No. V202043.

Disclosed herein are compositions and methods related to mutant viruses, and in particular, mutant influenza viruses. The mutant viruses disclosed herein include mutant M2 sequences, mutant BM2 sequences, and are useful in immunogenic compositions, e.g., as a quadrivalent vaccines. Also disclosed herein are methods, compositions and cells for propagating the viral mutants, and methods, devices and compositions related to vaccination.

The present disclosure discloses a whole avian-origin reverse genetic manipulation system and its use in producing a recombinant H7N9 avian influenza vaccine. The whole avian-origin reverse genetic manipulation system is an eight-plasmid reverse genetic manipulation system based on H5N2 subtype avian influenza D7 virus strain, which is comprised of 8 recombinant plasmids respectively containing PB2, PB1, PA, HA, NP, NA, M and NS gene fragments derived from H5N2 subtype avian influenza D7 virus strain. The genome of the recombinant H7N9 subtype avian influenza vaccine of the present disclosure is comprised of an NA gene and a modified HA gene derived from a highly pathogenic H7N9 subtype avian influenza virus strain, as well as PB2, PB1, PA, NP, M and NS genes derived from H5N2 subtype avian influenza D7 virus strain.

Engineered Influenza polynucleotides, viruses, vaccines, and methods of making and using the same are provided. More specifically, the present inventors have developed replication competent engineered influenza viruses having, for example, a modified segment 4 and/or segment 6 that include at least one additional polynucleotide encoding a heterologous polypeptide.

Provided is a method of producing reassortant influenza virus containing an antigenic protein of the first influenza virus strain, the method including the following steps: 1) a step of irradiating the first influenza virus strain with ultraviolet light in such an irradiation dose that the first influenza virus strain has initial infection ability and loses or is reduced in virus growth potential; 2) a step of infecting a host with the first influenza virus strain and the second influenza virus strain; 3) a step of culturing the host infected with the first influenza virus strain and the second influenza virus strain, to obtain culture product; 4) a step of inactivating influenza virus strain having an antigenic protein of the second influenza virus strain in the culture product obtained in the step 3); and 5) a step of collecting reassortant influenza virus after the step 4).

The present invention provides a modified influenza A virus (IAV) comprising, consisting of, or consisting essentially of at least one artificial gene segment comprising a duplicated packaging signal, the result of which is a modified IAV that is replication competent and avirulent, and when co-infected with a wild type virus leads to segment exchange and compromises the spread of both viruses as well as methods of making and using same and methods of using the IAVs in the treatment and prevention of influenza-related diseases.

The disclosure relates to defective interfering genes and viruses thereof. It has been discovered that defective interfering genes designed from influenza and coronavirus species can inhibit infection or replication of the parent virus. In vivo, DIGs induce rapid-onset prophylactic protection of infected animals against lethal viral doses. Thus, disclosed herein are nucleic acids containing DIGs, pharmaceutical compositions thereof and associated methods of use. For example, described herein is an isolated polynucleotide containing one or more defective interfering genes, wherein each of the one or more defective interfering genes contains a nucleotide sequence corresponding to one or more portions of an influenza or coronavirus gene or genome, wherein the nucleotide sequence includes a deletion in the gene. The DIGs can be in the form of a plasmid. Pharmaceutical compositions of the plasmid can be used to limit viral replication and prevent or treat influenza or coronavirus associated diseases.

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.

An isolated recombinant influenza virus is provided having PA, PB1, PB2, NP, NS, M, NA and HA viral segments, wherein the PB1 viral segment encodes a PB1 with a residue other than isoleucine at position 711 or the M viral segment encodes a M1 with a residue other than methionine at position 128, wherein the recombinant influenza virus has enhanced replication relative to a corresponding influenza virus having a PB1 viral segment that encodes a PB1 with an isoleucine at position 711 or having a M viral segment that encodes a M1 with methionine at position 128, as well as methods of making and using the virus.