The present disclosure discloses a novel coronavirus SARS-COV-2 safe replicon system and use thereof in screening an anti-SARS-COV-2 drug. The safe replicon system specifically comprises a nucleic acid sequence encoding a novel coronavirus SARS-COV-2 non-structural protein; and nucleic acid sequences of 5 UTR and 3 UTR of a novel coronavirus SARS-COV-2, a transcription regulatory region on which the novel coronavirus SARS-COV-2 non-structural protein can act, and a reporter gene. With the SARS-COV-2 safe replicon system, high-throughput screening of anti-SARS-COV-2 drugs and pharmacologic verification of drugs can be carried out independent of a biosafety level 3 laboratory, and the operation is simple and convenient.

Provided herein are peptide VLP vaccines that deliver at least one immunogenic antigen to a subject and induce a protective immune response in the subject. Additionally, provided are related methods and compositions.

Described herein are methods and compositions for directing an antibody response in a subject away from one or more first epitopes of an antigen (e.g., immunodominant epitopes of a vaccine antigen) and towards one or more second epitopes of the antigen by administering one or more antibodies targeting the one or more first epitopes of the antigen.

The present invention provides an infectious bronchitis virus (IBV) spike protein (S protein) which is based on an S protein from an IBV strain with restricted tissue tropism, but which comprises the sequence XBBXBX in the part of the S2 protein corresponding to residues 686 to 691 of the sequence given as SEQ ID No. 2, where B is a basic residue and X is any amino acid; and which comprises at least one of the following amino acid substitutions with reference to the position numbering of SEQ ID NO:2: Leucine (L) to Phenylalanine (F) at position 578 Asparagine (N) to Serine (S) at position 617 Asparagine (N) to Serine (S) at position 826 Leucine (L) to Phenylalanine (F) at position 857 and Isoleucine (I) to Valine (V) at position 1000 such that an IBV virus comprising the S protein has extended tissue tropism. The present invention also provides a virus comprising such an S protein.

CRISPR RNA-guided nucleases are routinely used for sequence-specific manipulation of DNA. While CRISPR-based DNA editing has become routine, analogous methods for editing RNA have yet to be established. Here we repurpose the type III-A CRISPR RNA-guided nuclease for sequence-specific cleavage of the SARS-CoV-2 genome. The type III cleavage reaction is performed in vitro using purified viral RNA, resulting in sequence-specific excision of 6, 12, 18 or 24 nucleotides. Ligation of the cleavage products is facilitated by a DNA splint that bridges the excision and RNA ligase is used to link the RNA products before transfection into mammalian cells. The SARS-CoV-2 RNA is infectious and standard plaque assays are used to recover viral clones. Collectively, this work demonstrates how type III CRISPR systems can be repurposed for sequence-specific editing of RNA viruses including SARS-CoV-2 and more generally for gene therapy.

Provided herein are compositions and methods for inducing an immune response in a subject, wherein the compositions comprise apoptotic cells, extracellular vesicles (EVs), and combinations thereof. Various compositions comprising mRNA encoding a microbial antigen are also provided. Further provided herein are compositions engineered to overexpress the human arrestin domain containing protein 1 [ARRDC1].

The present disclosure relates to a HR1-derived polypeptide comprising 10 or more consecutive amino acids of the polypeptide of SEQ ID NO. 8 as disclosed in the description, or a polypeptide derivative thereof. This disclosure also concerns an immunogenic composition comprising a HR1-derived polypeptide as described herein. It also relates to an immunogenic composition comprising a nucleic acid encoding a HR1-derived polypeptide as described herein. In some preferred embodiments, the said nucleic acid consists of a ribonucleic acid.

A fusion protein containing the full length SARS-CoV-2 spike protein, or the S1 domain or the S2 domain of the SARS-CoV-2 spike protein or a fragment, or the human Angiotensin Converting Enzyme 2 (ACE2) receptor of the SARS-CoV-2 spike protein or a fragment, and a N-terminal signal peptide, and at least one of the following: a polyhistidine tag, a streptavidin binding domain, a linker, or an oligomerization tag.

The invention discloses vaccine for coronavirus and influenza virus and method for preparation thereof. More specifically, the invention discloses seasonal viral vaccine i. e. coronavirus and influenza virus vaccine for prophylaxis of novel coronavirus (SARS-CoV-2) infection (COVID-19) and Influenza virus in mammals and method for preparation of such vaccine. The invention discloses the stable combination vaccine compositions of killed-inactivated SARS-CoV-2, Influenza virus (A and B strains) as antigens. The present invention further discloses method of adaptation and growth seasonal influenza (A and B) strains in cell culture and methods of inactivation and purification of influenza virus bulk antigen. The present invention also discloses SARS-CoV-2 vaccine formulation with inactivated Influenza viruses and use of the same to elicit immune response against the SARS-CoV-2 and Influenza viruses in mammals and humans.

CRISPR RNA-guided nucleases are routinely used for sequence-specific manipulation of DNA. While CRISPR-based DNA editing has become routine, analogous methods for editing RNA have yet to be established. Here we repurpose the type III-A CRISPR RNA-guided nuclease for sequence-specific cleavage of the SARS-COV-2 genome. The type III cleavage reaction is performed in vitro using purified viral RNA, resulting in sequence-specific excision of 6, 12, 18 or 24 nucleotides. Ligation of the cleavage products is facilitated by a DNA splint that bridges the excision and RNA ligase is used to link the RNA products before transfection into mammalian cells. The SARS-COV-2 RNA is infectious and standard plaque assays are used to recover viral clones. Collectively, this work demonstrates how type III CRISPR systems can be repurposed for sequence-specific editing of RNA viruses including SARS-COV-2 and more generally for gene therapy.