TABLE 1.

Kinetics of the cellular immune response to serovar Typhi Ty21aa

No. of days after vaccinationFrequency of respondersb
T-cell proliferationIFN-γ production
30/20/2
76/86/8
144/86/8
213/84/8
361/22/2
  • a Peripheral blood T cells were stimulated with 107 heat-killed serovar Typhi Ty21a bacteria/ml.

  • b A significant response is defined as a >2-fold increase in the rate of proliferation or IFN-γ production compared to the level before vaccination in either the CD4+- or the CD8+-T-cell population. Values are numbers of vaccinees who responded/total numbers of vaccinees.