Research Information System
5. Uluslararası Aşı Bilimi Kongresi, Kayseri, Turkey, 16 October - 18 December 2024, pp.46-47
Objective: Hazara virus (HAZV) belongs to the genus Orthonairovirus within the Nairoviridae family of the
order Bunyavirales and shares the same genus with Crimean-Congo hemorrhagic fever virus (CCHFV).
Crimean-Congo hemorrhagic fever (CCHF), caused by CCHFV, poses a significant public health threat due
to its high mortality rate and the absence of effective treatments or vaccines, necessitating research under
biosafety level (BSL) 4 conditions. In contrast, while HAZV belongs to the same serogroup, it has not been
reported to cause any disease in humans, allowing it to serve as a model for CCHFV and be studied under
less restrictive BSL-2 conditions.
Methods: Antigenic similarities between HAZV and CCHFV were first reported approximately 40 years
ago, but these findings have been updated in only a limited number of studies. The potential of HAZV to
serve as a model virus for CCHFV is of particular significance for vaccine research. In this study, antigenic
similarities between the two viruses were evaluated using CCHFV immune sera from different species
(human, mouse, rabbit) by performing enzyme immunoassays (EIA) against whole HAZV. For this purpose,
HAZV was cultured in the BHK-21 cell line, and the virus was purified using sucrose gradient centrifugation
followed by fast protein liquid chromatography (FPLC) with using Capto™ Core 700 column. The purified
HAZV antigen was used as a base antigen in EIAs, and cross-reactivity with CCHFV immune sera was tested,
confirming antigenic similarities between the two viruses.
Results and Conclusion: The findings of this study demonstrate that HAZV can be utilized as a model for
CCHFV and that the two viruses exhibit significant antigenic similarities in the context of humoral immune
response. However, further studies are required to evaluate the potential of HAZV as a vaccine candidate.
Specifically, its immunogenicity and protective efficacy should be thoroughly investigated in different
animal models and preclinical studies. Such research will help better understand the potential of HAZV
for use in the development of vaccines and therapeutic strategies against CCHFV.