Correlation between humoral immune responses and presence of virus in the CNS in dogs experimentally infected with canine distemper virus.

The role of the humoral immune response in clearance or prevention of canine distemper viral encephalitis of dogs infected with a virulent strain of canine distemper virus has been evaluated. Dogs that have demyelinating lesions, CDV proteins and infectious virus in their brains demonstrate an impaired humoral immune response. In dogs that recover from infection and contain no demyelinating lesions, viral proteins or infectious virus in the brain, antibodies to the internal proteins of CDV are observed early after infection. Later antibodies to primarily the H protein are detectable in sera of these dogs and the appearance of antibodies against the surface glycoprotein (H) correlates with the absence of lesions, CDV antigen and infectious virus in the brains of these dogs. Very late after infection immunoprecipitating antibody to all CDV antigens diminished rapidly so that at about ten weeks post infection antibodies that precipitate CDV antigens are barely detectable.