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Influenza A Virus Studies in a Mouse Model of Infection
Published on: September 7, 2017
Field avian metapneumovirus evolution avoiding vaccine induced immunity
Elena Catelli1, Caterina Lupini, Mattia Cecchinato
1Dipartimento di Sanità Pubblica Veterinaria e Patologia Animale, University of Bologna, Ozzano Emilia (BO), Italy. elena.catelli@unibo.it
Vaccine
|November 26, 2009
Summary
Live avian metapneumovirus (AMPV) vaccines control turkey rhinotracheitis (TRT), but outbreaks persist. Recent AMPV field strains have evolved antigenically, reducing vaccine effectiveness in turkeys.
Area of Science:
- Veterinary Virology
- Avian Pathology
Background:
- Live avian metapneumovirus (AMPV) vaccines have controlled turkey rhinotracheitis (TRT) in Europe.
- Unexplained TRT outbreaks continue to occur despite widespread vaccination.
Purpose of the Study:
- To investigate the genetic and antigenic evolution of AMPV field strains in Italy.
- To assess the efficacy of current vaccines against contemporary AMPV isolates.
Main Methods:
- Longitudinal farm studies involving AMPV detection in turkeys.
- Whole-genome sequencing of AMPV isolates.
- Experimental challenge of vaccinated turkeys with field isolates.
Main Results:
- Subtype B AMPVs detected post-vaccination were genetically distinct from vaccine strains.
- Sequencing revealed significant differences in SH and G protein genes of recent isolates compared to older strains and vaccines.
- Vaccinated birds showed inferior protection against recent field virus compared to an earlier isolate.
Conclusions:
- Field strains of AMPV have evolved antigenically, particularly in key surface protein genes.
- Viral evolution has আউটপুটed vaccine-induced immunity, leading to disease in vaccinated turkeys.
- Ongoing monitoring and vaccine updates are necessary to manage evolving AMPV strains.
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