ESTIMATION OF ANTIGEN-RESPONSIVE T-CELL FREQUENCIES IN PBMC FROM HUMAN-SUBJECTS

We describe a consulting project in which the statisticians found that they needed to develop a new method of analysis in order to reach val id conclusions about the effect of a herpes vaccine on the immune syst ems of human subjects. This method estimates the frequency of blood ce lls responding to a viral antigen at a single, carefully chosen diluti on. The traditional analysis of such data uses a cutoff to separate ex perimental sites (''wells'') which contain no responding cells from we lls which contain at least one responding cell, whereas our method use s the scintillation count to estimate the actual number of responding cells for each well. We describe the experiment in some detail, as we found that one of the major challenges facing the statisticians was th e need to understand the biology in enough detail to provide a relevan t model.