Protective Activity of Inactivated Rabies Vaccine Using Flagellin-Based Adjuvant

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Olga O. Sokol¹, Nikolai A. Nikitin^2,a*, Ekaterina A. Evtushenko², Olga V. Karpova², Irina N. Matveeva^1,3, Svetlana A. Gryn¹, Vera M. Popova¹, Igor V. Ivanov¹, Yuri N. Fedorov¹, and Irina Y. Litenkova³

¹All-Russian Scientific Research and Technological Institute of Biological Industry, 141142 Biocombinat, Moscow Region, Russia

²Faculty of Biology, Lomonosov Moscow State University, 119234 Moscow, Russia

³Shchelkovo Biocombinat Federal State Enterprise, 141142 Biocombinat, Moscow Region, Russia

Received October 6, 2023; Revised January 19, 2024; Accepted March 1, 2024

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Rabies is a zoonotic disease with high lethality. Most human deaths are associated with the bites received from dogs and cats. Vaccination is the most effective method of preventing rabies disease in both animals and humans. In this study, the ability of an adjuvant based on recombinant Salmonella typhimurium flagellin to increase protective activity of the inactivated rabies vaccine in mice was evaluated. A series of inactivated dry culture vaccine for dogs and cats “Rabikan” (strain Shchelkovo-51) with addition of an adjuvant at various dilutions were used. The control preparation was a similar series of inactivated dry culture vaccine without an adjuvant. Protective activity of the vaccine preparations was evaluated by the NIH potency test, which is the most widely used and internationally recommended method for testing effectiveness of the inactivated rabies vaccines. The value of specific activity of the tested rabies vaccine when co-administered with the adjuvant was significantly higher (48.69 IU/ml) than that of the vaccine without the adjuvant (3.75 IU/ml). Thus, recombinant flagellin could be considered as an effective adjuvant in the composition of future vaccine preparations against rabies virus.

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KEY WORDS: rabies, inactivated vaccine, adjuvant, flagellin, specific activity, NIH-test

DOI: 10.1134/S0006297924030155

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