Rabbit haemorrhagic disease: experimental study of a recent highly pathogenic GI.2/RHDV2/b strain and evaluation of vaccine efficacy
| Autor: | A. Nicolier, M. Sourice, L. Joudou, T. Le Moullec, S. Boucher, A. Sigognault-Flochlay, O. Le Minor, R. Mellet, F. Beilvert |
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| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Efficacy
040301 veterinary sciences efficacy Spleen Context (language use) Rabbit haemorrhagic disease (RHD) Virus 0403 veterinary science Rabbit haemorrhagic disease 03 medical and health sciences vaccine medicine pathogenicity Pathogenicity Feces 030304 developmental biology lcsh:SF1-1100 rabbit haemorrhagic disease (RHD) 0303 health sciences lcsh:Veterinary medicine biology RT-qPCR 04 agricultural and veterinary sciences biology.organism_classification Vaccine efficacy Virology GI.2/RHDV2 Vaccination Reverse transcription polymerase chain reaction medicine.anatomical_structure lcsh:SF600-1100 Animal Science and Zoology lcsh:Animal culture Vaccine |
| Zdroj: | RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia instname World Rabbit Science, Vol 27, Iss 3, Pp 143-156 (2019) |
| DOI: | 10.4995/wrs.2019.11082 |
| Popis: | In 2010, a variant of the rabbit haemorrhagic disease virus (RHDV) belonging to a new GI.2 genotype was identified in France and rapidly spread worldwide. Due to antigenic difference, new vaccines including G1.2 strains have been developed to confer adequate protection. An increase in the pathogenicity of the circulating strains was recently reported. The objective of this experimental study was to characterise the infection with a highly pathogenic GI.2/RHDV2/b isolate (2017) and assess the efficacy of Filavac VHD K C+V vaccine (Filavie) against this strain. Four and 10-wk-old specific pathogen-free rabbits were inoculated with a recommended dose of vaccine. After 7 d, controls and vaccinated rabbits were challenged and clinically monitored for 14 d. All animals were necropsied and blood, organs and urine were sampled for quantitative reverse transcription polymerase chain reaction (RT-qPCR) analysis. In adult groups, regular nasal and rectal swabbing were performed, and faeces were collected after death to monitor RNA shedding. In control groups, the challenge strain induced acute RHD between 31 and 72 h post-inoculation, with a mortality rate of 100% for kits and 89% for adult rabbits. Except for a shorter mean time to death in kits, similar clinical signs and lesions were observed between age groups. The vaccination significantly prevented all mortality, clinical signs, detection of viral RNA in serum and gross lesions in kits and adult rabbits. In adult groups, we also demonstrated that vaccine significantly protected from detectable RNA shedding via naso-conjunctival and rectal routes. Two weeks after challenge, RNA copies were not detected by PCR in the liver, spleen, lungs, kidneys, faeces and urine of vaccinated adult rabbits. The findings for kits were similar, except that very low levels of RNA were present in the liver and spleen of a few rabbits. These data show that immunisation prevented any significant viral multiplication and/or allowed a rapid clearance. We concluded that, despite the quick evolution of GI.2/RHDV2/b strains, the protection conferred by the vaccine remains adequate. In the context of coexistence of both GI.1 and GI.2 genotypes in some countries, with the circulation of multiples recombinant viruses, the vaccination should be based on the association of strains from both genotypes. |
| Databáze: | OpenAIRE |
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