The PPD-specific T-cell clonal response in UK and Malawian subjects following BCG vaccination: A new repertoire evolves over 12 months

Pre-vaccination antigen specific T-cell clones were detected, but the majority of clones present 12 months after vaccination were not present earlier. The magnitude of the clonal response did not correlate well with results of the other assays. These data indicate that single assays may not be reliable and that a stable memory T-cell repertoire is slow to develop.