Production of Antibody in Chicken Flocks Involved in Single and Double Infection with Herpes Virus of Turkey and Marek's Disease Virus

Abstract

SPF day-old chicks were divided into three groups. Group 1 was inoculated with herpes virus of turkey (HVT). Group 2 was exposed to contact infection with Marek's disease virus (MDV). Group 3 was inoculated with HVT and exposed immediately to contact infection with MDV.As a result, group 1 showed a higher positive rate of antibody against HVT antigen than against MDV antigen when examined by the agar gel precipitation test (AGP), and a high antibody titer when examined by the indirect fluorescent antibody technique (IFA). Group 2 exhibited a higher positive rate or antibody titer against MDV antigen than against HVT antigen. Group 3 revealed the production of antibody against double infection with HVT and MDV.
A survey was conducted on a poultry farm where Marek's disease had broke out frequentlyin spite of inoculation with HVT vaccine. When examined by AGP, the production of antibodyagainst HVT and MDV was apparent at 5 weeks of age and later, suggesting the “take” of vaccine and the contamination with MDV. The virus infection was confirmed by the virus isolation. When examined by IFA, the production of antibody against HVT was noticed, but that ofantibody against MDV was not, although MDV infection occurred to many of chicks within 2 weeks after HVT inoculation.