The present invention relates to expression of SARS-CoV like virus proteins [S, M and E] proteins; recombinant polynucleotides, polypeptides; constructs, virus-like particles (VLPs); immunogenic compositions or vaccines comprising Virus Like Particles (VLPs). Method of producing the VLPs/expressing the multi-subunit virus like proteins and method for co-expression of multi-subunit and virus like proteins (VLPs) are also provided. The present invention also provides strategies, methods, systems, kits and combinations for scalable expression, purification and enhanced production of the virus like proteins of SARS-CoV while maintaining their size range and composition. Such multi-subunit VLPs can be utilized to make immunogenic compositions or vaccines.

Provided are a bovine rotavirus fusion protein and calf diarrhea multivalent vaccine. The bovine rotavirus fusion protein contains a VP6 fragment, wherein the VP6 fragment contains an amino acid sequence as represented by SEQ ID NO. 4, and at least one loop region of the following (a)˜(c) is substituted with an antigenic epitope derived from bovine coronavirus and/or an antigenic epitope derived from E. coli: (a) amino acid residues of sites 168-177, with an amino acid sequence as represented by SEQ ID NO. 1; (b) amino acid residues of sites 194-205, with an amino acid sequence as represented by SEQ ID NO. 2; and (a) amino acid residues of sites 296-316, with an amino acid sequence as represented by SEQ ID NO. 3, The bovine rotavirus fusion protein contains a plurality of antigenic epitopes, and can enable a host to generate a plurality of antibodies after immunizing the host.

Disclosed are compositions and methods for increasing Rotavirus production.

The present invention relates to immunogenic compositions comprising recombinantly constructed polypeptides useful for preparing vaccines, in particular for reducing one or more clinical signs caused by a rotavirus infection. More particular, the present invention is directed to an immunogenic composition containing (i) a fusion protein comprising in N- to C-terminal direction (A) an immunogenic fragment of a rotavirus VP8 protein and (B) an immunoglobulin Fc fragment such as, for example, an IgG Fc fragment, and (ii) an immunogenic substance, different from said fusion protein, wherein said immunogenic composition is usable in a method of reducing one or more clinical signs, mortality or fecal shedding caused by a rotavirus infection in swine.

Provided are a bovine rotavirus fusion protein and calf diarrhea multivalent vaccine. The bovine rotavirus fusion protein contains a VP6 fragment, wherein the VP6 fragment contains an amino acid sequence as represented by SEQ ID NO. 4, and at least one loop region of the following (a)?(c) is substituted with an antigenic epitope derived from bovine coronavirus and/or an antigenic epitope derived from E. coli: (a) amino acid residues of sites 168-177; with an amino acid sequence as represented by SEQ ID NO. 1; (b) amino acid residues of sites 194-205; with an amino acid sequence as represented by SEQ ID NO. 2; and (a) amino acid residues of sites 296-316, with an amino acid sequence as represented by SEQ ID NO. 3, The bovine rotavirus fusion protein contains a plurality of antigenic epitopes, and can enable a host to generate a plurality of antibodies after immunizing the host.

Rotavirus vectors encoding in their genome a heterologous gene, and nucleic acid constructs encoding such rotavirus vectors. The rotavirus vector genome may include a rotavirus non-structural protein, a 2A peptide downstream of the rotavirus non-structural protein, and a heterologous protein downstream of the 2A peptide. The heterologous gene may be, for example, a SARS-CoV-2 spike protein or a fragment thereof, or an RSV F protein or a fragment thereof.

The present application relates to a method for producing a reassortant Reoviridae virus and a vector library for the same, and provides: a method for producing a reassortant Reoviridae virus by using a cell line into which an RNA polymerase is introduced and an expression vector library according to an aspect; a reassortant Reoviridae virus produced by the method; and an expression vector library for producing reassortant rotavirus.

The invention relates to a method for preparing double-layered virus-like particles of rotavirus in vitro. The method comprises the following steps: purifying rotavirus VP6 proteins from a lysis supernatant, and in vitro assembling double-layered virus-like particles consisting of VP2 proteins and VP6 proteins, wherein the proteins and the virus-like particles can be used for preventing or reducing the clinical symptoms caused by rotavirus infection.

The present invention relates to a method for preparing a reassortant rotavirus, and provides a reverse genetics platform using an inhibitory RNA as selective pressure for the reassortant rotavirus. Through the method, reassortment probability dramatically increases so that a desired reassortant rotavirus can be prepared in a short time and at low cost.

The present invention relates to expression of SARS-CoV like virus proteins [S, M and E] proteins; recombinant polynucleotides, polypeptides; constructs, virus-like particles (VLPs); immunogenic compositions or vaccines comprising Virus Like Particles (VLPs). Method of producing the VLPs/expressing the multi-subunit virus like proteins and method for co-expression of multi-subunit and virus like proteins (VLPs) are also provided. The present invention also provides strategies, methods, systems, kits and combinations for scalable expression, purification and enhanced production of the virus like proteins of SARS-CoV while maintaining their size range and composition. Such multi-subunit VLPs can be utilized to make immunogenic compositions or vaccines.