Provided herein is a method of functionalizing a particle, as well as methods of optically tracking a particle, isolating enveloped viral particles from a sample, quantifying enveloped virus particles in a sample and assessing enveloped viral aggregation in a sample. Kits are also provided. The particle is typically a viral particle.

The disclosure provides for an isolated recombinant influenza virus having at least one of: a PA gene segment encoding PA with a residue at position 443 that is not arginine, a PB1 gene segment encoding PB1 with a residue at position 737 that is not lysine, a PB2 gene segment encoding PB2 with a residue at position 25 that is not valine or a residue at position 712 that is not glutamic acid, a NS gene segment encoding a NS1 with a residue at position 167 that is not proline, a HA gene segment encoding a HA with a residue at position 380 that is not threonine, or any combination thereof, and methods of making and using the virus.

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 subject invention pertains to isolated influenza virus that is capable of infecting canids and causing respiratory disease in the canid. The subject invention also pertains to compositions and methods for inducing an immune response against an influenza virus of the present invention. The subject invention also pertains to compositions and methods for identifying a virus of the invention and diagnosing infection of an animal with a virus of the invention.

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.

Disclosed are viruses, and vaccines comprised of and made from such viruses, that include a heterologous nucleic acid segment encoding α-1,3-galactosyltransferase (α-1,3-GT) such that the nucleic acid segment expresses α-1,3-GT when the virus infects a host cell. Such viruses produce proteins having α-1,3-galactose. The presence of α-1,3-galactose on proteins of infected cells can powerfully stimulate the immune response of the host against the viral proteins of the virus, thus enhancing the effect of the virus as a vaccine. Also disclosed are vaccines that include and/or are produced by such viruses. Also disclosed are methods of making and using such viruses and vaccines, such as administering to a subject in need thereof a vaccine as disclosed and such as making a vaccine that includes one or more viral proteins expressed by a virus as disclosed.

The invention provides an influenza virus that demonstrates enhanced growth in Vero cells. The influenza virus includes PA, NP, and NS gene segments having selected nucleotides and encoding proteins having amino acid sequences with selected amino aids. The invention also provides a pharmaceutical formulation containing the influenza virus, as well as a method of eliciting an immune response in a mammal by administering the influenza virus to the mammal, and a method for generating the influenza virus.

Modified influenza virus neuraminidases are described herein that improve viral replication, thus improving the yield of vaccine viruses. Expression of such modified neuraminidases by influenza virus may also stabilize co-expressed hemagglutinins so that the hemagglutinins do not undergo mutation or decrease the need for HA binding to cells.

The invention provides a recombinant biologically contained influenza virus that is a PB2 knockout virus, e.g., one that is useful to generate a multivalent vaccine, and methods of making and using that virus.

The disclosure provides for an isolated recombinant influenza virus having at least one of: a PA gene segment encoding PA with a residue at position 443 that is not arginine, a PB1 gene segment encoding PB1 with a residue at position 737 that is not lysine, a PB2 gene segment encoding PB2 with a residue at position 25 that is not valine or a residue at position 712 that is not glutamic acid, a NS gene segment encoding a NS1 with a residue at position 167 that is not proline, a HA gene segment encoding a HA with a residue at position 380 that is not threonine, or any combination thereof, and methods of making and using the virus.