Vaccination of SCT recipients

Abstract

Last year several scientific organizations collaborated in drafting the guidelines for prevention of infections after hematopoietic SCT (HSCT).1, 2 One set of guidelines dealt with vaccination of transplant recipients and in these guidelines the conjugated heptavalent pneumococcal vaccine (PCV7; Prevnar; Pfizer Inc.) was recommended based on several studies showing both immunogenicity and safety of this vaccine in HSCT recipients. Earlier this year, a 13-valent vaccine (Prevnar13; Pfizer Inc., New York, NY, USA), which is produced in a similar way to the 7-valent vaccine, was licensed in both the USA and Europe after the completion of large clinical trials in healthy children. This vaccine contains the same seven pneumococcal serotype antigens contained in the PCV7 together with antigens from additional six serotypes. After licensure, it was decided that the heptavalent vaccine will be withdrawn from the market and therefore the published recommendations cannot be followed. Presently, a clinical trial is ongoing with this 13-valent vaccine in allogeneic HSCT recipients. In addition, a 10-valent pneumococcal vaccine (Synflorix; GlaxoSmithKline, London, UK) conjugated to another carrier protein has also been licensed in Europe for which no data yet exist in immunocompromised patients. The alternative to these conjugated vaccines is polysaccharide vaccines that have shown decreased immunogenicity compared with conjugate vaccines in allogeneic HSCT recipients. Despite the lack of data, we recommend that the 13-valent vaccine be used as replacement for the heptavalent vaccine when this is no longer available, until additional studies are performed.