The humoral immune response after BCG vaccination: an immunoblotting study using two purified antigens.

The specific IgG response induced by BCG vaccination was investigated in 27 adults using two purified BCG antigens in a dot immunoblotting assay. The reflectance values increased significantly after vaccination when P64 but not when P32 was used as the antigen. The values measured after vaccination were compared with those obtained when testing sera from patients with tuberculosis. We observed that the level of anti-P64 IgG reached after BCG immunization was high enough to preclude a serological differential diagnosis with tuberculosis.