Protection of Chickens against Marek's Disease Virus JM-V Strain with Statolon and Exogenous Interferon

The effect of interferon and statolon on Marek's disease virus in baby chickens was studied. Exogenous interferon induced by Newcastle disease virus (NDV) in chicken embryos was administered intra-abdominally (IA) daily for 14 days into 3 groups of chickens infected by IA inoculation of the JM-V strain of MD virus (MD-JMV). Interferon administration was initiated simultaneously with virus in the first group, 72 hours after virus inoculation in the second group, and 168 hours after in the third group. Survival rate was 17.3%o when interferon administration was initiated simultaneously with virus (3.3% in untreated controls). Survival decreased as interferon treatment was delayed. A single dose of statolon of 500 mg/kg gave survival rates up to 56.8% (5% or less in untreated controls). Time of administration was critical, with protection being maximum with statolon given 24 hours after virus. Statistical analysis indicated that chicks were protected significantly against MD by administration of statolon from 24 hours before virus inoculation up to 72 hours after. The protective effect of statolon correlated with its interferoninducing capacity, suggesting that interferon is the mediator of the antiviral action.