The Design And Immunogenicity Of SARS-CoV-2 RBD Recombination Protein Vaccine And Peptide Vaccine

COVID-19 has seriously affected global public health,vaccine is still the most effective means to control the spread of the epidemic.The comprehensive evaluation of vaccine includes effectiveness,safety,production cost,production speed,storage and transportation.In this study,we not only designed RBD recombinant protein vaccine,but also designed peptide vaccine based on SARS-Co V-2 virus.The main contents are as follows:COVID-19 binds to angiotensin converting enzyme 2(ACE-2)on the surface of host cells through its RBD of spike protein,and mediates the entry of the virus into host cells.Therefore,in this study,the Fc fusion RBD recombinant protein was efficiently obtained by mammalian expression system.Within three months after immunization,the neutralizing antibody titer of BALB / c mice not only maintained a high level,but also had the ability to induce cellular immunity.Moreover,there was no obvious damage to lung and kidney tissue after immunization,which proved its effectiveness and safety.In addition,to deal with the impact of virus mutation on existing vaccines.In this study,we predicted viral epitopes by bioinformatics and screened twenty-one candidate epitopes.Based on the prediction,KLH coupled peptide vaccine were prepared.After immunizing BALB/c mice,the immunogenicity of SP＿497-505,SP＿529-537,SP＿680-689 and NP＿185-195 were not satisfied.In order to overcome the problem of immunogenicity of single epitope peptide,we further designed and prepared the peptide self-assembly nano-vaccine.The method can assemble ten different antigen peptides to form the same polypeptide self-assembly nanoparticles at the same time,which lays the foundation for the development of multi epitope vaccine.Therefore,this study not only provides a more diverse choice for the design of COVID-19 vaccine,but also provides a reference for the development of other coronavirus vaccines.