• Investigating the immunogenicity of corona vaccine candidate (S1) produced in prokaryotic host
  • Ramin Ahadzadegan Ahani,1 Tina Hassan Panah,2,* Fataneh Fatemi,3 Seyyed Omid Ranaee Siadat,4
    1. Protein Research Center, Shahid Beheshti University, Tehran, Iran
    2. Protein Research Center, Shahid Beheshti University, Tehran, Iran
    3. Protein Research Center, Shahid Beheshti University, Tehran, Iran
    4. Protein Research Center, Shahid Beheshti University, Tehran, Iran


  • Introduction: The new human coronavirus has a very high treatment cost and still shows a high death rate in infected people. If the vaccine is widely used, we will have a lower rate of coronavirus infection. Making this vaccine is important and its results can be used in research centers and pharmaceutical companies. Several laboratories around the world have begun conducting studies to develop a vaccine to prevent the disease. Most of the vaccines targeted the specific protein subunit of the glycoprotein of SARS-CoV (S1). Coronavirus uses this glycoprotein to bind and enter host cells. Therefore, a vaccine that creates a strong immune response against this protein will have a significant effect in preventing the virus from entering host cells during natural infection.
  • Methods: Materials used: 1. Aluminum hydroxide adjuvant. Aluminum salts are the most common adjuvants in the preparation of human and animal vaccines. Aluminum hydroxide adjuvant shows good immunoadjuvant effects with many antigens. 2. The new S1 protein was expressed as a recombinant protein in the Soban Recombinant Protein Company in a prokaryotic vector, and after purification and exchange of buffer with a mass of 200 μg/ml, it was prepared for combination with adjuvant. 3. Sodium Chloride (NaCl) Sodium Chloride was used to prepare a salt buffer in order to dilute the sample obtained from the combination of adjuvant and protein. How to do the work: Formulation of the vaccine. Next, we refer to the stages of preparing the vaccine. 1. Preparation of adjuvant stock buffer 3. Examining the binding of adjuvant to S1 protein. After combining the appropriate ratio of protein and aluminum hydroxide adjuvant, the vaccine sample was placed in a cold room for 24 hours, and after that, tests were carried out to ensure the binding of protein and adjuvant. SDS-PAGE analysis and Lowry test can be mentioned among the performed investigations. 4. Determining the immunogenic variables and drawing the injection table, the injection process was done according to different conditions using insulin injection syringes to Balb C mice.
  • Results: As a result, in this project, the s1 protein was recombinantly expressed in the prokaryotic host. The purified protein with the formulated formulations was examined for injection into the rat animal sample. This formulation is composed of protein and aluminum hydroxide adjuvant with ratios of 1:5 and 1:10. Injections were given at intervals of 14 and 21 days to check immunogenicity. The number of prescribed doses was 2 and 3 injections. The results of this project determined that ratios of 1:10 produced higher antibody titers than 1:5. In blood sampling 14 days after the first injection, a low antibody level was observed in all formulations. Then, with the increase in the number of injections, the antibody level increased. With the third injection after 35 days, the antibody titer grew exponentially.
  • Conclusion: In short, the goals of the upcoming research are: creating maximum immunogenicity using protein (S1) against corona in the presence of a suitable adjuvant, reducing the country's treatment costs in dealing with corona by creating immunity against coronavirus, optimizing the method to improve the quality of the produced vaccine by conducting animal tests (mouse) to ensure the accuracy of the function of the recombinant protein (S1) of the coronavirus, the production of a recombinant protein vaccine that has an appropriate ratio of (S1) adjuvant that stimulates the immune system well and can be used on an industrial scale. The implementation steps of the research are: 1. The production of protein conjugated with aluminum hydroxide (adjuvant) 2. Injection into the animal 3. Taking blood from the animal 4. ELISA kit to determine the antibody titer is generally the step of this research. Coronavirus is a very dangerous virus that has a high cost of treatment and a high mortality rate, that's why it is very important to produce a vaccine that causes immunity against the virus, which can reduce the number of infections and deaths. As a result of reducing the rate of infection and death due to coronavirus and reducing the medical costs of the country, the surface polysaccharide of coronavirus (S1) may be a suitable candidate for making a vaccine and creating immunity against coronavirus.
  • Keywords: Vaccine candidate; coronavirus; immunogenicity; Adjuvant; S1 protein