Persistence of humoral and cell-mediated immunity to rubella virus in cloistered nuns and in schoolteachers.

Humoral and cell-mediated immunity to rubella virus after naturally acquired infection were compared in 19 cloistered nuns (29-79 years of age), 18 female schoolteachers (21-61 years of age), and 21 female control subjects (20-30 years of age), who were all seropositive for rubella virus, by use of a hemagglutination-inhibition test, a passive hemagglutination test, a hemolysis-in-gel test, a radioimmunoassay, an enzyme-linked immunosorbent assay, and lymphocyte transformation tests. No significant differences were found among the groups by the radioimmunoassay, the hemolysis-in-gel test, and the enzyme-linked immunosorbent assay. The cloistered nuns had significantly lower cell-mediated immunity to rubella virus than did the teachers and the control subjects but nonetheless showed protective levels of antibody to rubella virus and significant lymphocyte transformation responses, which persisted until age 79 in the probable absence of reinfection.