Randomized Study of Early versus Late Immunization with Pneumococcal Conjugate Vaccine after Allogeneic Stem Cell Transplantation

Abstract

We conclude that PCV7 vaccination at 3 months after stem cell transplantation is not inferior to PCV7 vaccination at 9 months after transplantation. Because invasive pneumococcal disease can occur early, we recommend starting the PCV7 vaccination series at 3 months after transplantation to ensure earlier protection against Streptococcus pneumoniae. However, the early vaccination may result in only short-lasting response and may not prime for a 23-valent pneumococcal polysaccharide vaccine boost as efficiently as the late vaccination.