Streptococcus pneumoniae, also known as Pneumococcus, is a common cause of pneumonia in transplant patients. There has been a vaccine available for this infection called Pneumovax. Recently, a new vaccine for this infection called Prevnar has been developed which may be more effective. Vaccinating the bone marrow donor before transplant may boost the recipient's immune response to the vaccine after transplant. This study is done to compare how vaccinating the donor with one of the vaccines will affect the recipient's immune system response to the vaccine.
This is a randomized controlled trial designed to assess the immunogenicity of the new pneumococcal conjugate vaccine in a cohort of allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients. This will be done by using an approach of pre-transplant donor immunization with post-transplant recipient immunization. Response will be compared with the standard 23-valent polysaccharide vaccine. It is hypothesized that the conjugate vaccine will provide an enhanced response in this group of immunosuppressed individuals who respond poorly to standard polysaccharide vaccines. Specific objectives of this study are: * To determine the antibody response to both vaccines via a measurement of total antibody response and by the opsonophagocytic assay. This assay has the advantage of assessing if patient antibody responses represent truly functional antibodies that display opsonic activity against pneumococcus and is likely better correlated with protective efficacy. * To determine any acute adverse reactions of the conjugate vaccine in this population. Results of this trial will help lay the foundation for the development of a rationale and optimal pneumococcal vaccination strategy that would prevent significant morbidity in this patient population. We hypothesize that pneumococcal conjugate vaccine, due to its T-cell dependent response will have greater immunogenicity and protective effect in an allo-HSCT population by using a donor immunization strategy.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
DOUBLE
University Health Network-Princess Margaret Hospital
Toronto, Ontario, Canada
Immunogenicity of two vaccines via a determination of serotype specific capsular antibody formation and functional antibody formation from donor and recipient serum.
All patients will be called by telephone 24 hours after receiving vaccine to determine if any acute adverse events occurred. Any occurance of pneumococcal disease in recipients for one year post-transplant during the study period will be recorded.
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Enrollment
70