Repeated Challenge with Virulent Newcastle Disease Virus Does Not Decrease the Efficacy of Vaccines
| Autor: | Timothy L. Olivier, Claudio L. Afonso, Dawn Williams-Coplin, Enrique Montiel, Tonya L. Taylor, Kiril M. Dimitrov, Stivalis Cardenas Garcia, Patti J. Miller |
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| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Newcastle Disease Newcastle disease virus Virulence Chick Embryo Antibodies Viral Newcastle disease Virus 03 medical and health sciences Immune system Food Animals Animals General Immunology and Microbiology biology Antibody titer Viral Vaccines Clinical disease biology.organism_classification Antibodies Neutralizing Virology Vaccination 030104 developmental biology Immunology biology.protein Animal Science and Zoology Antibody Chickens |
| Zdroj: | Avian Diseases. 61:245-249 |
| ISSN: | 1938-4351 0005-2086 |
| DOI: | 10.1637/11555-120816-resnote.1 |
| Popis: | Globally, poultry producers report that birds well-vaccinated for Newcastle disease (ND) often present clinical disease and mortality after infection with virulent strains of Newcastle disease (vNDV), which is contrary to what is observed in experimental settings. One hypothesis for this discrepancy is that the birds in the field may be exposed to multiple successive challenges with vNDV, rather than one challenge dose, and that the repeated infection may overwhelm the immune system and neutralizing antibodies available to prevent clinical disease. In this study, we evaluated this hypothesis under highly controlled conditions. We challenged well-vaccinated chickens with high doses of vNDV daily for 10 days, and looked for signs of clinical disease, changes in antibody titers, and mortality. All sham-vaccinated birds died by the fourth day postchallenge. No morbidity or mortality was observed in any of the NDV-vaccinated birds up to 14 days postchallenge; repeated high-dose challenges of vNDV was not sufficient to overcome vaccine immunity. |
| Databáze: | OpenAIRE |
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