Abstract: Disclosed are a SARS-COV-2 antigen polypeptide, a recombinant adeno-associated virus (rAAV) expressing the polypeptide, and a vaccine containing the virus. A sequence of the antigen polypeptide is shown in SEQ ID NO: 1 and SEQ ID NO: 2. A method for preparing the recombinant adeno-associated virus comprises co-incubating pHelper, pRep2Cap5, and an expression vector, transfecting a cell in the presence of polyethyleneimine as a transfection reagent; culturing the cell, then collecting the cell by centrifugation, performing lysis and purification to obtain a purified liquid comprising the recombinant adeno-associated virus. The rAAV is delivered and expressed in vivo to produce a fusion antigen polypeptide, induces the production of serum neutralizing antibodies, which have a neutralizing titer to the novel SARS-COV-2 coronavirus and are expressed continuously; the rAAV composition can be used to immunize humans against the novel coronavirus pneumonia COVID-19.

Abstract: The present application provides a helper plasmid for preparing a recombinant adeno-associated virus (rAAV), including: 1) a coding sequence of an AAV Rep protein and a coding sequence of an AAV Cap protein; 2) at least one promoter sequence; and 3) at least one DA?sequence or AD? sequence, wherein the AD? sequence is a reverse complementary sequence of the DA? sequence. The present application also provides a method for increasing a production capacity of a rAAV using the helper plasmid. With an AD? sequence or a DA? sequence, the helper plasmid provided in the present application can significantly increase an AAV yield of a cell.

Abstract: Disclosed are a SARS-COV-2 antigen polypeptide, a recombinant adeno-associated virus (rAAV) expressing the polypeptide, and a vaccine containing the virus. A sequence of the antigen polypeptide is shown in SEQ NO. 1. and SEQ ID NO. 2. A method for preparing the recombinant adeno-associated virus comprises co-incubating pHelper, pRep2Cap5, and an expression vector, transfecting a cell in the presence of polyethyleneimine as a transfection reagent; culturing the cell, then collecting the cell by centrifugation, performing lysis and purification to obtain a purified liquid comprising the recombinant adeno-associated virus. The rAAV is delivered and expressed in vivo to produce a fusion antigen polypeptide, induces the production of serum neutralizing antibodies, which have a neutralizing titer to the novel SARS-COV-2 coronavirus and are expressed continuously; the rAAV composition can be used to immunize humans against the novel coronavirus pneumonia COVID-19.