The question is examining the feasibility of using fractional dose of the wP containing vaccine to protect adolescents and adults. In an era of combination vaccines where different antigens are being licensed for mixing with other antigen/combination manufactured separately- some even at different production units (for example DTP+Hep B with Hib conjugate vaccine), the suggestion of Dr Paul seems quite tempting and worth considering, especially for our country where significant disease burden coupled with exorbitant cost of the aP vaccines make it impossible to even think of exercising the option of using aP vaccines at mass level. However, to recommend such a practice, we need to have evidence of safety as well as of efficacy of the revised practice that can only be obtained through clinical trials. Further, the effect of such practices on the frequency of serious adverse events and on protection against disease has not been determined earlier. Hence, in the absence of such a data, IAPCOI can not recommend this alternative practice of using fractional dose of whole-cell pertussis vaccine for adolescent and adult vaccination.