A Crimean-Congo hemorrhagic fever (CCHF) viral vaccine expressing nucleoprotein is immunogenic but fails to confer protection against lethal disease

Abstract

Crimean-Congo Hemorrhagic Fever (CCHF) is a severe tick-borne disease, endemic in many countries in Africa, the Middle East, Eastern Europe and Asia. Between 15–70% of reported cases are fatal with no approved vaccine available. In the present study, the attenuated poxvirus vector, Modified Vaccinia virus Ankara, was used to develop a recombinant candidate vaccine expressing the CCHF virus nucleoprotein. Cellular and humoral immunogenicity was confirmed in 2 mouse strains, including type I interferon receptor knockout mice, which are susceptible to CCHF disease. Despite the immune responses generated post-immunisation, the vaccine failed to protect animals from lethal disease in a challenge model.

Keywords:

• Crimean-Congo hemorrhagic fever, nucleoprotein, protection, vaccine

Disclosure of Potential Conflicts of Interest

No potential conflicts of interest were disclosed.

Acknowledgments

The authors would like to thank the staff of the Biological Investigations Group at PHE Porton for their technical expertise in conducting the animal experiments and Laura Hunter for processing histopathology samples. The views expressed in this publication are those of the author(s) and not necessarily those of the UK Department of Health.