Novel Immunostimulant for Potentiating Vaccine Efficacy in Animal Rabies Immunization

Anahita Bahmanjeh¹ Zahra Jalali² Farzaneh Malekpour³ Mohsen Enayatsefat⁴ Parivash Ghaderinia⁵ Seyyed Danial Mirmiran⁶ Roxanna Jamali⁷

1) Department of Virology Vaccines, Production and Research Unit, Pasteur Institute of Iran, Karaj, Iran
2) Department of Quality Control, Pasteur Institute of Iran,
3) Department of Medical Microbiology, Faculty of Medicine, Shahrekord University of Medical Sciences, Shahrekord, Iran
4) Department of Microbiology, Faculty of Science, Islamic Azad University, Science and Research Branch, Tehran, Iran
5) Department of Microbiology, Zanjan Branch, Islamic Azad University, Zanjan, Iran
6) State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University Wuhan, China
7) Department of Biomedical Sciences, University of Saskatchewan, Saskatchewan, Canada

IOI Code : AAAB-ABBKEK
Publication : 2nd International Congress on Engineering Sciences and Sustainable Urban Development(dtuconf.com)
Abstract :
    Introduction: Rabies remains a significant global challenge to public health, where immunization serves as the primary preventive strategy. Currently licensed inactivated rabies vaccines frequently necessitate repeated administration and are limited by the absence of strong adjuvants to boost their effectiveness. The objective of this research was to examine the linkage of fully inactivated rabies virus with mannan through an oxidative process as a method to augment immunological reactions relative to a conventional rabies vaccine. Specifically, the study focused on conjugating the inactivated virus with oxidized mannan (referred to as Rab-OxMan). Materials and Methods: Mice received intraperitoneal immunizations of 350 µg of the Rab-OxMan preparation on days 1 and 7. Serum was obtained two weeks post-vaccination to quantify IgG, IgM, and TNF-α concentrations via ELISA. Vaccine strength was further assessed using the standard NIH test protocol. Results: The results indicated a statistically significant elevation in IgG and a reduction in IgM titers in the Rab-OxMan cohort relative to the group receiving the alum-adjuvanted vaccine (p<0.05). TNF-α concentrations were also substantially increased in the Rab-OxMan-treated animals (p<0.05). Analytical evaluations identified IgG levels as possessing the greatest diagnostic sensitivity and specificity, with strong inter-parameter correlations observed. Crucially, in vivo protection assays demonstrated that the Rab-OxMan formulation conferred 1.8-fold higher protective immunity compared to the alum-based vaccine group. Conclusion: This work represents the inaugural report establishing oxidized mannan as an innovative adjuvant candidate for animal rabies vaccines. The outcomes underscore marked enhancements in both the immune-potentiating capacity and protective performance of the vaccine, indicating a viable approach to advance rabies prophylaxis and possibly lower the prevalence of this fatal infection.

Keywords : rabies vaccine inactivated rabies nih immunogenicity