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A Chinese Variant Marek’s Disease Virus Strain with Divergence between Virulence and Vaccine Resistance
- Source :
- Viruses; Volume 9; Issue 4; Pages: 71, Viruses, Viruses, Vol 9, Iss 4, p 71 (2017)
- Publication Year :
- 2017
- Publisher :
- MDPI AG, 2017.
-
Abstract
- Marek’s disease (MD) virus (MDV) has been evolving continuously, leading to increasing vaccination failure. Here, the MDV field strain BS/15 was isolated from a severely diseased Chinese chicken flock previously vaccinated with CVI988. To explore the causes of vaccination failure, specific-pathogen free (SPF) chickens vaccinated with CVI988 or 814 and unvaccinated controls were challenged with either BS/15 or the reference strain Md5. Both strains induced MD lesions in unvaccinated chickens with similar mortality rates of 85.7% and 80.0% during the experimental period, respectively. However, unvaccinated chickens inoculated with BS/15 exhibited a higher tumor development rate (64.3% vs. 40.0%), but prolonged survival and diminished immune defects compared to Md5-challenged counterparts. These results suggest that BS/15 and Md5 show a similar virulence but manifest with different pathogenic characteristics. Moreover, the protective indices of CVI988 and 814 were 33.3 and 66.7 for BS/15, and 92.9 and 100 for Md5, respectively, indicating that neither vaccine could provide efficient protection against BS/15. Taken together, these data suggest that MD vaccination failure is probably due to the existence of variant MDV strains with known virulence and unexpected vaccine resistance. Our findings should be helpful for understanding the pathogenicity and evolution of MDV strains prevalent in China.
- Subjects :
- 0301 basic medicine
China
lcsh:QR1-502
Virulence
Biology
Marek’s disease virus
lcsh:Microbiology
Article
Virus
Microbiology
03 medical and health sciences
Immune system
Virology
evolution
Marek Disease
vaccination failure
virulence
pathogenicity
vaccine efficacy
Animals
Treatment Failure
Marek's disease
Strain (chemistry)
Inoculation
Viral Vaccines
biology.organism_classification
Vaccine efficacy
Mardivirus
030104 developmental biology
Infectious Diseases
Flock
Chickens
Subjects
Details
- ISSN :
- 19994915
- Volume :
- 9
- Database :
- OpenAIRE
- Journal :
- Viruses
- Accession number :
- edsair.doi.dedup.....bc0dcac9564bb2f6670a898fb80f8bd5
- Full Text :
- https://doi.org/10.3390/v9040071