Pertussis Immunity and Response to Tetanus-Reduced Diphtheria-Reduced Pertussis Vaccine (Tdap) after Autologous Peripheral Blood Stem Cell Transplantation

Pertussis is a highly contagious respiratory infection characterized by prolonged cough and inspiratory whoop. Despite widespread vaccination of children aged < 7 years, its incidence is steadily increasing in adolescents and adults, because of the known decrease in immunity following childhood immunization. In an effort to reduce pertussis in adolescents and adults, 2 vaccines containing tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) (BOOSTRIX and Adacel) were licensed in 2005 for use in adolescents, I of which (Adacel) contains less pertussis toxoid (PT) for use in adults. This study assessed pertussis titers in 57 adult survivors of an autologous peripheral blood stem cell transplantation (PBSCT; median age, 37.5 years), 28 of whom were subsequently vaccinated with Tdap containing 2.5 mu g of PT (Adacel). The median time to Tdap administration was 3 years posttransplantation. Before vaccination, 87% of the patients lacked pertussis immunity. Only 2 of the 28 patients developed a >2-fold response to PT following vaccination with Tdap. These data suggest that autologous transplantation recipients are highly susceptible to pertussis and that immunization with 2.5 mu g of PT induces an inadequate response. Prospective trials evaluating BOOSTRIX, containing 8 mu g/dose of PT (approved for adults in December 2008) are warranted in this vulnerable population undergoing transplantation. Biol Blood Marrow Transplant 15: 1538-1542 (2009) (C) 2009 American Society for Blood and Marrow Transplantation