Persons without a spleen are susceptible to potentially lethal infections from certain bacteria, with pneumococcus being the most prevalent. Vaccines are provided to help protect against these infections, though they do not so with certainty. Trauma patients who sustain an injury to their spleen currently have three treatment options available for the treating surgeon - nonoperative management, embolization, or removal of the spleen. The purpose of this study is to investigate the antibody response to pneumococcal vaccine in patients undergoing these modes of therapy.