AGE-RELATED DIFFERENCES IN CELLULAR IMMUNE RESPONSE TO RUBELLA

POSSIBLE IMPLICATIONS IN VACCINE REACTOGENICITY

Abstract

Studies were made on the development of rubella-specific cell-mediated immune (CMI) response in different age groups of rubella-seronegative normal subjects at various intervals after subcutaneous inoculation of attenuated live HPV-77/DE5 rubella vaccine. The technique of in-vitro lymphocyte transformation (LTF) was used and the Putnam strain of rubella virus as antigen. The rubella-specific CMI response of children ranging from two to twelve years of age was characterized by a significant LTF activity appearing two months after inoculation, which exhibited a gradual decrease after that. The CMI response to rubella of subjects 18 to 35 years of age was a little slow initially to appear. The maximum LTF activity of these adult subjects was three to four times lower (P<0.01) than that of the children. There was no difference in maximum antibody titer to rubella virus between these two groups of subjects. These results suggested that the age-related difference in the lymphoprolif erative response might be associated with the adverse effects of the rubella vaccine which had been known to occur more frequently in adolescent and adult patients than in infant and child patients after the establishment of vaccine-induced rubella infection.