The present disclosure provides polypeptides, and nucleic acids encoding the polypeptides, that include severe acute respiratory syndrome Co-V-2 (SARS-CoV-2) spike polypeptide receptor-binding domain (RBD) polypeptides or variants thereof, which are capable of multimerization and thus presenting multiple copies of the RBD to enhance the immune response generated when the polypeptide is administered to a subject. The disclosure also provides multimers, scaffolds, compositions, pharmaceutical compositions, and vaccines that include the polypeptides and/or nucleic acids that encode such polypeptides.

This application provides materials and methods related to replication competent, noninfectious coronavirus reporter replicons, such as for SARS-CoV-2, MERS, or SARS-CoV-1 comprising at least one coronavirus gene and at least one reporter gene. The application also provides methods for assaying candidate agents for inhibition of coronavirus viral replication.

The invention provides competitive particles, such as virus-like particles, RNAs and DNAs for the treatment or prevention of viral infections and methods of using such particles for treating or preventing or reducing the risk of viral infections (or symptoms thereof) in a subject, such as a human or animal subject. For example, the method herein is a method of reducing or reducing the establishment of a zoonotic population of a virus in an animal, such as a livestock or wild animal (eg, a bat, camelid or a Pholidota (eg, a pangolin)).

Recombinant protein coronavirus antigens and vaccine compositions using the same, include a recombinant protein that is a single-chain (SC) viral membrane protein complex derived from the spike (S), envelop (E) and membrane (M) protein of a coronaviruses such as SARS-CoV-2, the causal agent for COVID-19. Methods for immunization of a subject using the vaccine compositions treats or prevents clinical signs caused by coronaviruses infection.

The COVID-19 pandemic has led to a worldwide health crisis and devastating economic and social issues. The present invention provides a method enhancing the effectiveness of the vaccines currently used for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which comprises three incremental doses of a vaccine to elicit an enhanced immune response against in a subject. The first dose, second dose, and final dose are administered in the amount of 10-25%, 45-55%, and about 100% of the vaccine's full-strength dose, respectively.

The present disclosure generally relates to the use of different self-amplifying RNA molecules to enhance immune responses, for example immune responses following prophylactic vaccination or therapeutic administration. Some embodiments relate to compositions and methods for inducing an immune response in a subject using prime-boost immunization regimens.

The present invention provides an electricity-driven, micro-electroporation based drug delivery system, in particular, an electrically conductive array of microprotrusions containing intended substances or molecules to be delivered, which is to the benefit of a recipient receiving vaccination transcutaneously in the absence of any assistive mechanical or actuation means as in conventional injection methods, so as to lower safety risks, improve immunization efficiency, and also induce immune response of the recipient more effectively at a relatively lower dose of vaccines.

The present invention provides an mRNA nanocapsule and use thereof, comprising a virus-like particle (VLP) formed by self-assembly of a plurality of capsid proteins (CPs), an mRNA encoding Cas13 protein, and a guide RNA. The mRNA includes a capsid protein binding tag to be encapsidated in the VLP, so that the mRNA can stably enter cells, and the Cas13 protein could be translated.

The present disclosure generally relates to the use of different self-amplifying RNA molecules to enhance immune responses, for example immune responses following prophylactic vaccination or therapeutic administration. Some embodiments relate to compositions and methods for inducing an immune response in a subject using prime-boost immunization regimens.

The present disclosure generally relates to the use of different self-amplifying RNA molecules to enhance immune responses, for example immune responses following prophylactic vaccination or therapeutic administration. Some embodiments relate to compositions and methods for inducing an immune response in a subject using prime-boost immunization regimens.