The present disclosure relates in some aspects to immunogenic compositions including recombinant peptides and proteins comprising coronavirus viral antigens and immunogens, e.g., coronavirus S protein peptides. In some aspects, the immunogenic composition comprises a secreted fusion protein comprising a soluble coronavirus viral antigen joined by in-frame fusion to a C-terminal portion of a collagen which is capable of self-trimerization to form a disulfide bond-linked trimeric fusion protein. In some aspects, the immunogenic compositions provided herein are useful for generating an immune response, e.g., for treating or preventing a coronavirus infection. In some aspects, the immunogenic compositions provided herein may be used in a vaccine composition, e.g., as part of a prophylactic and/or therapeutic vaccine. Also provided herein are methods for producing the recombinant peptides and proteins, prophylactic, therapeutic, and/or diagnostic methods, and related kits.

Disclosed herein are methods, systems, and compositions comprising genetically modified probiotic microorganisms. In some embodiments, the genetically modified probiotic microorganisms produce at least one viral coat protein and/or at least one fusion protein comprising an antigenic polypeptide linked to a viral coat protein.

Provided is a recombinant polypeptide containing at least one immunogenic fragment of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) spike glycoprotein, and pharmaceutical compositions containing the same.

An immunogenic CD40-targeted trimeric MERS-CoV S1 fusion polypeptide as well as a corresponding polynucleotide encoding it and its use for safely inducing immune responses directed against MERS-CoV without inducing vaccine associated respiratory pathologies associated with non-targeted vaccines.

An immunogenic CD40-targeted trimeric MERS-CoV S1 fusion polypeptide as well as a corresponding polynucleotide encoding it and its use for safely inducing immune responses directed against MERS-CoV without inducing vaccine associated respiratory pathologies associated with non-targeted vaccines.

Covalently modified polypeptide antigens having improved immunogenicity and/or stability, as well as compositions, cells, and methods relating thereto, are described herein. Polypeptide antigens are covalently conjugated to a one or more of steroid acid moieties to improve their stability and/or to trigger improved cellular immunity, or improved cellular and humoral immunity, against the antigen upon administration to a subject. The steroid acids include bile acids and bile acid analogs that enhance endocytosis and/or endosomal escape of endosomally trapped cargoes by potentiating enzymatic cleavage of sphingomyelin to ceramide within endosomal membranes. The steroid acid moieties may be pre-conjugated to a peptide, and the steroid acid-peptide moiety subsequently conjugated to the polypeptide antigen. The peptide may comprise one or more domains that impart an additional functionality to the modified polypeptide antigen.

Provided is a recombinant polypeptide containing at least one immunogenic fragment of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) spike glycoprotein, and pharmaceutical compositions containing the same.

An immunogenic CD40-targeted trimeric MERS-CoV S1 fusion polypeptide as well as a corresponding polynucleotide encoding it and its use for safely inducing immune responses directed against MERS-CoV without inducing vaccine associated respiratory pathologies associated with non-targeted vaccines.

An immunogenic CD40-targeted trimeric MERS-CoV S1 fusion polypeptide as well as a corresponding polynucleotide encoding it and its use for safely inducing immune responses directed against MERS-CoV without inducing vaccine associated respiratory pathologies associated with non-targeted vaccines.

Compositions and methods are provided for potent mRNA vaccines for prevention and treatment of 2019 novel Coronavirus (2019-nCoV) infections. The compositions include a pharmaceutical composition containing one or more mRNA molecules encoding spike protein epitopes, including mutated epitopes, or mRNA cocktails that encode critical viral genes together with pharmaceutically acceptable polymeric nanoparticle carriers and liposomal nanoparticle carriers. Methods for stimulating system immune responses and treatment are provided, including subcutaneous, intraperitoneal and intramuscular injections.