[Long-term persistence of the vaccinia virus in a child with a congenital skin disease].

Persistence of vaccinia virus which was isolated many times from the blood and skin lesions was discovered in a child vaccinated 6 years before against smallpox and suffering from bullous epidermolysis. The level of immunoglobulins A, M, and G was normal, whereas the titre of virus-neutralizing antibodies against smallpox was low (1:10) in the child, and reached 1:320 in his mother not vaccinated against smallpox. Humoral immunity for other antigens was found to be unimpaired, the skin tests being positive. It was concluded that the child had a selective defect of the immune system. It is emphasized that the virus excretor is epidemically hazardous for subjects with skin diseases, immunodeficient conditions and others, in whom contraction of the infection may result in a disease the identification of the genesis of which would be extremely difficult against the background of discontinued vaccination against smallpox.