CMV Viremia; This literature-non-study case was reported in a literature article and describes the occurrence of CYTOMEGALOVIRUS VIRAEMIA (CMV Viremia) in a 67-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 prophylaxis.   LITERATURE REFERENCE:     The patient's past medical history included Heart transplant. Concurrent medical conditions included Non-ischemic cardiomyopathy. Concomitant products included TACROLIMUS and MYCOPHENOLATE MOFETIL (MYCOPHENOLATE) for Immunosuppression.    On an unknown date, the patient received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. In 2021,  after starting mRNA-1273 (Moderna COVID-19 Vaccine), the patient experienced CYTOMEGALOVIRUS VIRAEMIA (CMV Viremia) (seriousness criterion medically significant). The patient was treated with VALGANCICLOVIR (oral) at an unspecified dose and frequency. At the time of the report, CYTOMEGALOVIRUS VIRAEMIA (CMV Viremia) had resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Cytomegalovirus test (272-3.11): 1792 international unit per millilitre. On an unknown date, Lymphocyte count: 0.5. On an unknown date, SARS-CoV-2 antibody test: (Negative) Negative. On an unknown date, White blood cell count: 4.9.     For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter considered CYTOMEGALOVIRUS VIRAEMIA (CMV Viremia) to be related.    No concomitant medication was reported Time since heart transplant was reported as 18 months. Patient had no prior CMV infection. Cessation of prophylaxis before 1st CMV vaccine was reported as 2 months. No episode of rejection of after vaccination. Time from COVID-19 vaccination 2nd dose to positive CMV PCR was reported as 16 days. CMV status of donor and recipient was positive.  Company comment-This literature-non-study case, concerns a 67-year-old male patient, with reported medical history of Heart transplant for Non-ischaemic cardiomyopathy eighteen months back on Immunosuppression, who experienced the unexpected serious (medically significant) event of Cytomegalovirus viraemia that occurred in the context of second dose of mRNA-1273 vaccination. Latency cannot be assessed since vaccination date nor event onset date was disclosed. Patient was asymptomatic, with time from second dose of COVID-19 vaccination to positive CMV PCR as 16 days with no prior CMV infection reported. Time to serum CMV DNA PCR <200 was 7 days with CMV highest serum DNA PCR 1792 IU/mL. Cessation of prophylaxis before first CMV vaccine was reported as 2 months with no episodes of rejection after vaccination. On admission absolute lymphocyte count was 0.5 and leukocyte count was 4.9 with negative SARS-CoV-2 antibody test. Therapy included reduction of immunosuppression and oral valganciclovir. Patient had the resolution of CMV DNAemia by the censor date with a range of 7-58 day.  The riskbenefit assessment strongly favors COVID-19 vaccination for solid organ recipients, however, an increased awareness of a potentially associated risk of CMV reactivation may help care teams to more rapidly diagnose and manage this complication or perhaps consider short-term reinstitution of viral prophylaxis around the time of vaccination. The benefit-risk relationship of mRNA-1273 is not affected by this report.   This case was linked to MODERNATX, INC.-MOD-2022-645605, MODERNATX, INC.-MOD-2022-645826 (E2B Linked Report).   Most recent FOLLOW-UP information incorporated above includes: On 15-Sep-2022: Live follow up was received by safety on 15-SEP-2022 has Email and contains significant information: Reporter information, citation details, medical history, lab data, treatment medications, event details and clinical course details were updated. Sender's Comments: This literature-non-study case, concerns a 67-year-old male patient, with reported medical history of Heart transplant for Non-ischaemic cardiomyopathy eighteen months back on Immunosuppression, who experienced the unexpected serious (medically significant) event of Cytomegalovirus viraemia that occurred in the context of second dose of mRNA-1273 vaccination. Latency cannot be assessed since vaccination date nor event onset date was disclosed. Patient was asymptomatic, with time from second dose of COVID-19 vaccination to positive CMV PCR as 16 days with no prior CMV infection reported. Time to serum CMV DNA PCR <200 was 7 days with CMV highest serum DNA PCR 1792 IU/mL. Cessation of prophylaxis before first CMV vaccine was reported as 2 months with no episodes of rejection after vaccination. On admission absolute lymphocyte count was 0.5 and leukocyte count was 4.9 with negative SARS-CoV-2 antibody test. Therapy included reduction of immunosuppression and oral valganciclovir. Patient had the resolution of CMV DNAemia by the censor date with a range of 7-58 day.  The riskbenefit assessment strongly favors COVID-19 vaccination for solid organ recipients, however, an increased awareness of a potentially associated risk of CMV reactivation may help care teams to more rapidly diagnose and manage this complication or perhaps consider short-term reinstitution of viral prophylaxis around the time of vaccination. The benefit-risk relationship of mRNA-1273 is not affected by this report. MODERNATX, INC.-MOD-2022-645605:Same Article, 63 yrs Male. MODERNATX, INC.-MOD-2022-645826:Same Article, 42 yrs, male.