Abstract
Considerable differences between the Faulkner strain and recent isolates of coxsackievirus type B5 (CB5) have been found by RNA hybridization and virus neutralization tests. The differences are large enough to raise doubts on the use of the Faulkner strain as a prototype strain for the diagnosis of CB5 infections. The CB5 strains examined were also shown to differ from the serologically related swine vesicular disease virus (SVDV).