The present disclosure relates to development of a eukaryotic cell expression vector satisfying optimized conditions for gene therapies and DNA vaccines. As a result of replacing the full HCMV regulatory and transcribed region including the immediate early (IE) gene intron A of the HCMV Towne strain and the same region of various HCMV strains at the pVAX1 promoter region and comparing the difference in gene expression efficiency for the different HCMV strains, the eukaryotic cell expression vector of the present disclosure could increase the expression of various genes by about 50-150% as compared to the HCMV Towne strain. Through this, pHP3 was developed as a vector exhibiting high expression in eukaryotic cells, and it can be usefully used for gene therapies or DNA vaccines.

Disclosed herein are methods of forming compounds and exemplary stable compounds in the nature of a conjugated compound at refrigerated or room temperature, which in some embodiments comprises an antigen and virus particle mixed in a conjugation reaction to form a conjugate mixture, such that the conditions and steps of forming these products allow for use of the conjugate mixture as a vaccine, including but not limited to use as a vaccine against various pathogens including for treatment of diseases caused by novel coronaviruses (including SARS-COV 2).

The present disclosure provides compositions and methods for detecting the presence of neutralizing antibodies in a sample. Unlike conventional assays, the methods provided herein do not require the use of live virus or virus pseudoparticles to identify neutralizing antibodies.

Provided is a polypeptide containing the amino acid sequence as shown in SEQ ID NO. 1, and the present invention belongs to the field of biomedicine. The polypeptide can inhibit the infection with novel coronavirus 2019-nCoV (SARS-CoV-2) and SARS-like viruses, and can thus provide good candidate drugs for the prevention and treatment of 2019-nCoV and SARS-like viruses which may break out in the future. Further provided is a polypeptide derivative having palmic acid or cholesterol modifications.

The invention relates to an immunogenic or vaccine composition against the 2019 novel coronavirus (SARS-CoV-2), comprising a nucleic acid construct encoding a SARS-CoV-2 coronavirus Spike (S) protein antigen or a fragment thereof comprising the receptor-binding domain, wherein the nucleic acid construct sequence is codon-optimized for expression in human.

Disclosed herein include methods, compositions, and kits suitable for use in vaccination. There are provided, in some embodiments, nucleic acid compositions (e.g., mRNA vaccine, DNA vaccine) comprising a polynucleotide encoding a fusion protein. The fusion protein can comprise an antigenic polypeptide (AP) and an endosomal sorting complex required for transport (ESCRT)-recruiting domain (ERD). A plurality of fusion proteins can be capable of self-assembling into an enveloped nanoparticle (ENP) secreted from a cell in which the fusion proteins are expressed. There are provided, in some embodiments, populations of ENPs.

Provided is a vaccine composition including a recombinant DNA vaccine against a pathogen. The recombinant DNA vaccine includes an expression cassette operably linked to a promoter, and the expression cassette encodes a non-structural protein of a Sindbis virus and an antigenic protein of the pathogen. Also provided is a method of producing a protective immune response against a pathogen in a subject in need thereof by administering the vaccine composition to the subject.

The present disclosure provides particles for delivering a nucleic acid that encodes an immunogenic peptide in an antigen presenting cell. The disclosed particles can function as a vaccine and can be used to treat or prevent a viral or bacterial infection in a subject by expressing in vivo an immunogenic peptide, thereby stimulating the subject's immune system to attack the virus or bacteria that naturally express the immunogenic peptide.

Provided herein are recombinant modified vaccinia Ankara (rMVA) viral vectors comprising heterologous nucleic acid inserts encoding one or more SARS-CoV2 proteins, peptides, or fragments thereof, operably linked to a promoter compatible with poxvirus expression systems that, upon expression, are capable of inducing protective immunity. The compositions can be used in a priming vaccination strategy or in a prime/boost vaccination strategy to provide immunity to SARS-CoV2 and variants thereof.

An mRNA vaccine includes one or more polynucleotides and a pharmaceutically acceptable vector. Each polynucleotide includes a coding region. The coding region includes a gene of interest and a ligand sequence which encodes a CD40 ligand.