The development of a safe and effective vaccine to protect against COVID-19 is a global priority due to the current high SARS-CoV-2 infection rate. Currently, there are over 160 SARS-CoV-2 vaccine candidates at the clinical or pre-clinical stages of development. Of these, there are only three whole-virus vaccine candidates produced using β-propiolactone or formalin inactivation. Here, we prepared a whole-virus SARS-CoV-2 vaccine (SARS-CoV-2 PsIV) using a novel psoralen inactivation method and evaluated its immunogenicity in mice using two different adjuvants, alum and Advax-2. We compared the immunogenicity of SARS-CoV-2 PsIV against SARS-CoV-2 DNA vaccines expressing either full-length or truncated spike proteins. We also compared the psoralen-inactivated vaccine against a DNA prime, psoralen-inactivated vaccine boost regimen. After two doses, the psoralen-inactivated vaccine, when administered with alum or Advax-2 adjuvants, generated a dose-dependent neutralizing antibody responses in mice. Overall, the pattern of cytokine ELISPOT responses to antigen-stimulation observed in this study indicates that SARS-CoV-2 PsIV with the alum adjuvant promotes a Th2-type response, while SARS-CoV-2 PsIV with the Advax-2 adjuvant promotes a Th1-type response.
【저자키워드】 COVID-19, SARS-CoV-2, DNA vaccine, Prime-boost, psoralen-inactivated SARS-CoV-2 vaccine, anti-SARS-CoV-2-neutralizing antibodies, conformational epitopes of surface antigens, 4′-aminomethyl-4,5′,8-trimethylpsoralen (AMT), Advax-2, 【초록키워드】 Vaccine, SARS-COV-2 infection, adjuvants, cytokine, SARS-CoV-2 vaccine, DNA, mice, inactivation, vaccine candidate, Neutralizing antibody response, boost, Spike proteins, Safe, regimen, formalin, Stage, candidate, doses, full-length, Administered, effective, PROTECT, produced, evaluated, indicate, promote, dose-dependent, expressing, Th2-type, ELISPOT response, 【제목키워드】 immunogenicity, spike, DNA, BALB/c,