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Highly pathogenic avian influenza virus H5N1 from Egypt escapes vaccine-induced immunity but confers clinical protection against a heterologous clade 2.2.1 Egyptian isolate
- Source :
- Vaccine. 29:5567-5573
- Publication Year :
- 2011
- Publisher :
- Elsevier BV, 2011.
-
Abstract
- The poultry populations of Egypt are endemically infected by highly pathogenic avian influenza viruses (HPAIV) of subtype H5N1. Vaccination was chosen as an auxiliary tool to control HPAIV in poultry. Potency of commercial vaccines regarding emerging variants is under discussion. In the current study efficacy of four different inactivated whole H5 virus vaccines representing different sublineages of HPAIV H5N1 were tested in chickens against challenge viruses currently co-circulating in Egypt and representing two antigenically widely distinct HPAIV H5N1 lineages, i.e., "variant" (clade 2.2.1var) and "proper" (clade 2.2.1pro) viruses. All vaccines induced clinical protection against challenge with 2.2.1pro Egyptian strains. In contrast, when challenged with a variant strain, only chickens vaccinated with the homologous Egyptian clade 2.2.1var virus or an inactivated re-assorted H5N1 strain (Re-5, clade 2.3) were protected. However, only the homologous virus induced sterile immunity whereas chickens clinically protected after Re-5 vaccination shed virus at day two after infection indistinguishable to H5N2 vaccines. In conclusion, monitoring vaccine-driven evolution of HPAIV H5N1 by surveillance, antigenic characterization, and challenge studies is essential to assess efficacy of AIV vaccination campaigns.
- Subjects :
- animal diseases
Biology
medicine.disease_cause
Virus
Antigenic drift
Antigen
Immunity
medicine
Animals
Clade
Poultry Diseases
Influenza A Virus, H5N1 Subtype
General Veterinary
General Immunology and Microbiology
Strain (biology)
Public Health, Environmental and Occupational Health
virus diseases
Virology
Influenza A virus subtype H5N1
Virus Shedding
Vaccination
Infectious Diseases
Vaccines, Inactivated
Influenza Vaccines
Influenza in Birds
Molecular Medicine
Egypt
Chickens
Subjects
Details
- ISSN :
- 0264410X
- Volume :
- 29
- Database :
- OpenAIRE
- Journal :
- Vaccine
- Accession number :
- edsair.doi.dedup.....92a7331ba341c0494d7d42e2cbb1ee22