This study will enroll solid organ transplant recipients who develop cytomegalovirus infection and disease who have been treated. At the time of finishing treatment, if the clinician feels that secondary prophylaxis is indicated, they will be enrolled to receive Letermovir 480 mg orally once a day for 60 days. CMV specific T cell assays will be obtained at the initiation of secondary prophylaxis and at the discontinuation of secondary prophylaxis. Patients will be followed for 4 months following discontinuation of secondary prophylaxis to see if they relapse.
This is a research study to test the tolerability and clinical effectiveness of the study drug, Letermovir (LET), when used as secondary prophylaxis following treatment of Cytomegalovirus (CMV) infection and disease in a solid organ transplant recipient.~This study is an open label trial in which Letermovir will be prescribed to prevent the recurrence of CMV infection and disease in a solid organ transplant recipient following treatment of CMV infection or disease.