Age related differences in cellular immune response to vaccine induced rubella infection.

Employing the techniques of in-vitro lymphocyte transformation (LTF) and using Putnam strain of rubella virus as the antigen, the development of rubella specific cellular immune response was studied in different age groups of rubella seronegative normal subjects at various intervals after subcutaneous administration of HPV=77/DE5 live attenuated rubella vaccine. The rubella specific lymphocyte response in children ranging in age from two to twelve years was characterized by significant LTF activity at two months, followed by a gradual decrease. The response in adult subjects 18 to 35 years of age showed a slight delay initially in the appearance and the maximum LTF activity appeared to be 3--4 fold lower (P less than 0.01) than observed in the children. No difference was observed in the maximum antibody titers to rubella virus between these two groups of subjects. These observations suggest that the age related differences in the lymphoproliferative responses might be associated with adverse effects which are known to occur more frequently in adolescent and older patients than in childhood population after vaccine induced rubella infection.