Solid organ transplantation (SOT) has emerged as a lifesaving therapy for many patients with end organ failure. SOT recipients have a lifelong increased risk for infections as a result of immunosuppression, including those caused by pneumococci. The increased susceptibility to pneumococcal infections is multi-factorial and is related to underlying immunosuppression as well as varying degrees of splenic dysfunction as a result of underlying pretransplantation diseases, among other factors.