Infection and immunity with a virus isolate from turkeys

Area of Science:

• Veterinary Virology
• Avian Pathology

Background:

• Avian pox viruses cause significant economic losses in poultry farming.
• Commercial fowl pox vaccines are widely used but may not protect against all field isolates.
• Cutaneous pox lesions were observed in turkey breeders despite multiple vaccinations.

Purpose of the Study:

• To characterize a novel avian pox virus isolate from vaccinated turkey breeders.
• To evaluate the cross-immunogenicity of the isolate against other avian pox viruses.
• To determine the efficacy of homologous vaccination for protection.

Main Methods:

• Isolation and identification of the avian pox virus from turkey lesions.
• Cross-immunization experiments in turkeys and chickens using the isolate and other pox viruses.
• Assessment of protection against homologous and heterologous virus challenge.

Main Results:

• The turkey pox isolate, NC5271, demonstrated significant immunological differences from fowl, pigeon, and quail pox viruses.
• Homologous vaccination with the NC5271 isolate provided significant protection against infection.
• Heterologous vaccination did not confer significant protection, indicating a lack of cross-immunity.

Conclusions:

• The NC5271 isolate represents a distinct antigenic type of avian pox virus.
• Current commercial fowl pox vaccines may be insufficient for controlling this specific turkey pox strain.
• Development of a homologous vaccine is potentially necessary for effective disease control in turkey flocks.