Iranian Biomedical Journal

en Stability of Neutralizing Antibody of PastoCoAd Vaccine Candidates against a Variant of Concern of SARS-CoV-2 in Animal Models Molecular Immunology & Vaccines Molecular Immunology & Vaccines مقاله کامل Full Length/Original Article <div style="text-align: justify;">Background: Since the beginning of the SARS-CoV-2 pandemic, there have been mutations caused by new SARS-CoV-2 variants, such as Alpha, Beta, Gamma, Delta, and Omicron, recognized as the variants of concern (VOC) worldwide. These variants can affect vaccine efficacy, disease control, and treatment effectiveness. The present study aimed to evaluate the levels of total and neutralizing antibodies produced by PastoCoAd vaccine candidates against the VOC strains at different time points. Methods: Two vaccine candidates were employed against SARS-CoV-2 using adenoviral vectors: prime only (a mixture of rAd5-S and rAd5 RBD-N) and heterologous prime-boost (rAd5-S/SOBERANA vaccine). The immunogenicity of these vaccine candidates was assessed in mouse, rabbit, and hamster models using ELISA assay and virus neutralization antibody test. Results: The immunogenicity results indicated a significant increase in both total and neutralizing antibodies titers in the groups receiving the vaccine candidates at various time points compared to the control group (p < 0.05). The results also showed that the PastoCoAd vaccine candidates Ad5 S & RBD-N and Ad5 S/SOBERANA could neutralize the VOC strains in the animal models. Conclusion: The ability of vaccine candidate to neutralize the VOC strains in animal models by generating neutralizing antibodies at different time points may be attributed to the use of the platform based on the Adenoviral vector, the N proteins in the Ad5 S & RBD-N vaccine candidate, and the  SOBERANA Plus booster in the Ad5 S/SOBERANA vaccine candidate. </div> COVID-19 vaccines, Mutation, Nucleocapsid, Spike protein 214 220 http://ibj.pasteur.ac.ir/browse.php?a_code=A-10-4963-2&slc_lang=en&sid=1 Mohammad Panahi Mohammad.panahi.ali110@gmail.com 0000-0002-1045-1097 No Department of Hepatitis and AIDS, Pasteur Institute of Iran, Tehran, Iran Ali Teimoori teimooriali1982@gmail.com 0000-0003-0766-8591 No Department of Virology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran Saber Esmaeili dr.saberesmaeili@gmail.com 0000-0003-1920-1737 No National Reference Laboratory for Plague, Tularemia and Q Fever, Research Center for Emerging and Reemerging Infectious Diseases, Pasteur Institute of Iran, Akanlu, Kabudar Ahang, Hamadan, Iran Hossein Aminianfar aminianvetmed@gmail.com No Institute of Biomedical Research, University of Tehran, Tehran, Iran Alireza Milani a.milani@hotmail.com 0000-0003-0175-4800 No Department of Hepatitis and AIDS, Pasteur Institute of Iran, Tehran, Iran Seyed Younes Hosseini yovirus2002@yahoo.com 0000-0002-5881-6796 No Department of Bacteriology and Virology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran Parisa Esmaeili parisaesmaili27@yahoo.com 0000-0002-6427-8840 No National Reference Laboratory for Plague, Tularemia and Q Fever, Research Center for Emerging and Reemerging Infectious Diseases, Pasteur Institute of Iran, Akanlu, Kabudar Ahang, Hamadan, Iran Alireza Biglari biglari63@hotmail.com 0000-0002-3020-5889 No Pasteur Institute of Iran, Tehran, Iran Kazem Baesi kbaesi@gmail.com 0000-0001-5483-0008 Yes Department of Hepatitis and AIDS, Pasteur Institute of Iran, Tehran, Iran