ABSTRACT
Chinese painted quails immunized with a single dose (6 µg HA) of inactivated H5N1 (clade 1) influenza vaccine NIBRG-14 and challenged with 100 LD50 of the heterologous A/Swan/Nagybaracska/01/06(H5N1) (clade 2.2) strain were protected, whereas unvaccinated quails died after challenge. No viral antigens or RNA were detected in cloacal swabs from immunized animals. Sera obtained post-immunization gave low titres in serological assays against the vaccine and the challenge viruses. Our results demonstrate the protective efficacy of the NIBRG-14 strain against the challenge virus and the usefulness of these small birds in protection studies of influenza vaccines.
Subject(s)
Coturnix/virology , Influenza A Virus, H5N1 Subtype/immunology , Influenza Vaccines/immunology , Influenza in Birds/prevention & control , Vaccination/methods , Animals , Antibodies, Viral/blood , Cloaca/virology , Coturnix/immunology , Influenza Vaccines/administration & dosage , Influenza in Birds/immunology , Survival Analysis , Vaccines, Inactivated/administration & dosage , Vaccines, Inactivated/immunologyABSTRACT
In the southeast of Hungary a sparrow hawk (Accipiter nisus) and several goshawk (Accipiter gentilis) fledglings succumbed to encephalitis manifesting as an acute neurological disease during the summers of 2004 and 2005. Both years the causative agent was identified as a lineage 2 West Nile virus. This is the first description of clinical, pathological and immunohistochemical findings of infection caused by a neuroinvasive, lineage 2 West Nile virus and the first evidence of its circulation in continental Europe.