RANDOMIZED COMPARISON OF EARLY AND LATE VACCINATION WITH INACTIVATED POLIOVIRUS VACCINE AFTER ALLOGENEIC BMT

Forty-five adult HLA-matched sibling BMT recipients were randomized to receive inactivated poliovirus vaccine (IPV) at 6, 8 and 14 months (e arly group, n = 23) or at 18, 20 and 26 months after BMT (late group, n = 22), Ninety-five percent of the early group patients had protectiv e antibody titres of greater than or equal to 4 to poliovirus type 1 ( PV1), poliovirus type 2 (PV2) and poliovirus type 3 (PV3) by a microne utralization assay prior to the first vaccination, at 6 months after B MT, The corresponding proportion for the late group patients was only 67% at 18 months, The antibody responses 1 month after each of the thr ee IPV doses were similar in the two vaccination groups, except that f our-fold responses occurred more frequently after the first dose to PV 2 and PV3 in the late group, All patients had a protective antibody ti tre to all poliovirus serotypes 1 and 22 months after the third vaccin e dose, except one patient in the early group who lacked antibodies to PV3 at 22 months, Acute GVHD accelerated the decrease of poliovirus a ntibody titres prior to vaccination but had no influence on vaccinatio n response, Chronic GVHD neither influenced the patient's ability to r etain poliovirus antibodies prior to vaccination nor impaired response s to vaccinations, A vaccination schedule consisting of three IPV dose s was equally immunogenic when started at 6 or 18 months after allogen eic BMT.