This invention relates to immunogenic constructs, such as polynucleotides, polypeptides and multimeric proteins and to antigenic units and to pharmaceutical compositions/vaccines comprising such immunogenic constructs or antigenic units, which are useful for the prophylactic and therapeutic treatment of diseases caused by severe acute respiratory coronavirus 2 (SARS-CoV-2), as well as methods for producing and using the immunogenic constructs, antigenic units and pharmaceutical compositions/vaccines.

This application discloses a method for purifying pDNA, particularly pDNA that that can be used to produce RNA, the RNA preferably encoding a therapeutic or immunogenic peptide or polypeptide. The pDNA can be grown in a bacteria such as E. coli by culturing or fermenting bacteria containing the plasmid and obtaining and purifying the pDNA. The present method allows the pDNA to be obtained in high yield and with high purity. In one embodiment of the invention, the level of all non-pDNA materials can be significantly reduced by the process. In some embodiments, the ratio of supercoiled plasmid DNA (scDNA) to non-supercoiled pDNA (non-scDNA, such as open circular plasmid DNA (ocDNA)) can be increased by one or more process steps that separate or allow for separation of scDNA and ocDNA or process steps that increase the amount of scDNA to ocDNA.

The present invention relates to a novel cold-adapted attenuated Middle East respiratory syndrome coronavirus (MERS-CoV) and uses thereof. According to the present invention, the novel attenuated Middle East respiratory syndrome coronavirus (MERS-CoV) capable of effectively preventing infection with MERS-CoV has been developed by cold-adapting the MERS-CoV gradually, and thus can be effectively used as vaccines and therapeutic agents capable of preventing and treating Middle East respiratory syndrome.