Serologic studies of type II leukosis (Marek's) infection in susceptible (S-line) and resistant (K-line) strains of chicken by indirect hemagglutination test.

The indirect hemagglutination (IHA) test was used to investigate the difference in antigen and antibody response between genetically susceptible (S-line) and genetically resistant (K-line) chickens infected with JM virus either by natural exposure or artificial inoculation. The susceptible S-line had significantly higher levels of both IHA antigen and antibody titers than the K-line chicks over the age period of 4-8 weeks, indicating that S-line may provide a better cellular environment for growth and/or multiplication of a Type II leukosis agent than will K-line chicks. The IHA antibody possessed no significant neutralizing or protective ability. Although females are considered more susceptible to Type II leukosis, the sexes did not differ significantly in antibody or antigen titers. The control group developed no appreciable antigen or antibody titers.