Abstract: Provided are a cell strain HEK293.CS for reducing the production of a replication competent adenovirus, and a construction method and the use thereof. HEK293.CS is a safe adenovirus-producing cell line constructed by knocking out a gene fragment homologous to the Ad5 adenovirus E1 gene in HEK293 and providing a template plasmid to replace said gene fragment with a non-homologous sequence that stabilizes the expression of the E1 gene. Compared with the unmodified HEK293 cell strain, HEK293.CS shows no decrease in growth ability and virus production ability, but does not produce a detectable RCA. HEK293.CS can be used for the mass culture of a recombinant human type 5 adenovirus, and reducing the probability of RCA production in the manufacture process of drugs such as vaccines and antibodies.

Abstract: Provided are an mRNA or an mRNA composition, and an mRNA vaccine comprising the mRNA or the mRNA composition. The mRNA or the mRNA composition comprises an mRNA sequence encoding an S protein of a novel coronavirus SARS-CoV-2 or a variant thereof, and an mRNA sequence encoding an RBD in the S protein or a variant thereof. Further provided are the applications of the mRNA or the mRNA composition, and the mRNA vaccine comprising the mRNA or the mRNA composition in preparation of a medication for preventing and/or treating a disease caused by a novel coronavirus SARS-CoV-2 infection.

Abstract: Provided is a novel coronavirus vaccine using replication-deficient human type 5 adenovirus as a vector. The vaccine takes the replication-deficient human type 5 adenovirus that is lack of E1 and E3 in a combined mode as a vector, and HEK293 cells that integrate adenovirus E1 genes serve as a packaging cell line, and protective antigenic genes carried are optimized COVID-19 (SARS-CoV-2) S protein genes (Ad5-nCoV). The vaccine has good immunogenicity in both mouse and guinea pig models and can induce the body to produce a strong cellular and humoral immune responses in a short time. Research on the protective effect of hACE2 transgenic mice shows that 14 days after a single Ad5-nCoV immunization, the viral load in lung tissues can be significantly reduced. It shows that the vaccine has a good immune protection effect against COVID-19.

Abstract: Disclosed is an SamRNA vaccine, including a recombinant viral vector which includes: i) a viral gene replication complex including nucleotide sequences encoding viral gene replication-related proteins nsP1, nsP2, nsP3, and nsP4; and ii) a nucleotide sequence encoding at least one antigen. According to the SamRNA vaccine of the present invention, in addition to that a promoter of a modified adenoviral vector itself can transcribe an antigen gene to form mRNA, the viral gene replication-related proteins nsP1-4 use RNA as a template to synthesize a large amount of mRNAs, and the immune effect of a target antigen is greatly improved.

Abstract: Provided are a cell strain HEK293.CS for reducing the production of a replication competent adenovirus, and a construction method and the use thereof. HEK293.CS is a safe adenovirus-producing cell line constructed by knocking out a gene fragment homologous to the Ad5 adenovirus E1 gene in HEK293 and providing a template plasmid to replace said gene fragment with a non-homologous sequence that stabilizes the expression of the E1 gene. Compared with the unmodified HEK293 cell strain, HEK293.CS shows no decrease in growth ability and virus production ability, but does not produce a detectable RCA. HEK293.CS can be used for the mass culture of a recombinant human type 5 adenovirus, and reducing the probability of RCA production in the manufacture process of drugs such as vaccines and antibodies.