This literature-non-study case was reported in a literature article and describes the occurrence of CYTOMEGALOVIRUS VIRAEMIA (CMV Viremia) in a 56-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 prophylaxis.   LITERATURE REFERENCE:     The patient's past medical history included Heart transplant (8 months prior). Concurrent medical conditions included Non-ischaemic cardiomyopathy (Primary disease). Concomitant products included TACROLIMUS, MYCOPHENOLATE MOFETIL (MYCOPHENOLATE) and PREDNISONE for Immunosuppression.  In 2021, 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 GANCICLOVIR (intravenous) at an unspecified dose and frequency and VALGANCICLOVIR (oral) at an unspecified dose and frequency. In 2021, CYTOMEGALOVIRUS VIRAEMIA (CMV Viremia) had resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): In 2021, Blood immunoglobulin G: did not develop immunoglobulin G antibodies to SARS-CoV-2 in response to vaccination.. In 2021, Lymphocyte count: admission absolute lymphocyte count was 2.59. In 2021, Polymerase chain reaction: 3969 international unit per millilitre. In 2021, SARS-CoV-2 antibody test: (Negative) Negative. In 2021, White blood cell count: admission leukocyte count was 5.1.   For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter considered CYTOMEGALOVIRUS VIRAEMIA (CMV Viremia) to be related.    It was reported that donor cytomegalovirus status was positive and recipient status was negative.Cessation of prophylaxis before first CMV vaccine was reported as 2 months.Patient was not on CMV prophylaxis for at least 2 months before COVID-19 vaccination. Patient came off prophylaxis 6 months post-transplant.  Patient was asymptomatic. CMV disease state was reported as CMV Viremia.Time to serum CMV DNA PCR was reported as 16 days. Time from COVID-19 vaccination second dose to positive CMV PCR, was reported as 24 days.All patients were off antiviral prophylaxis either because of center or program protocol or  because of intolerance of prophylactic medications due to cytopenias, and they were on their standard immunosuppressive regimen at the time of vaccination. There were no documented cases of COVID-19 in these transplant recipients.  Authors discussed that by virtue of its observational nature, their study was  unable to draw a causal association between vaccination and CMV infections. However, all cases of CMV DNAemia described in their case series occurred in close temporal relation to patients receiving the mRNA-1273  COVID-19 mRNA vaccines supporting a strong possible role. None of these patients had CMV infections between the end of prophylaxis and the occurrence of CMV DNAemia after vaccination. Also, there was no rejection diagnosed in the 2 mo before CMV DNAemia, and thus augmentation of immunosuppression was not a contributing factor to CMV reactivation.  Authors concluded that  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.  Company Comment: This literature-non-study case, concerns a 56-year-old female patient, with reported medical history of Heart transplant for Non-ischaemic cardiomyopathy eight 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 24 days with no prior CMV infection reported. Time to serum CMV DNA PCR <200 was 16 days with CMV highest serum DNA PCR 3969 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 2.59 and leukocyte count was 5.1 with negative SARS-CoV-2 antibody test. Therapy included reduction of immunosuppression, intravenous ganciclovir followed by 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 US-MODERNATX, INC.-MOD-2022-645605, US-MODERNATX, INC.-MOD-2022-645823, US-MODERNATX, INC.-MOD-2022-645826, US-MODERNATX, INC.-MOD-2022-645824 (E2B Linked Report).   Most recent FOLLOW-UP information incorporated above includes: On 15-Sep-2022: Follow up received by safety on 15-Sep-2022 has email with full text article and contains significant information. Reporter information, literature information, medical history, laboratory data, product details  and event information was updated.; Sender's Comments: This literature-non-study case, concerns a 56-year-old female patient, with reported medical history of Heart transplant for Non-ischaemic cardiomyopathy eight 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 24 days with no prior CMV infection reported. Time to serum CMV DNA PCR <200 was 16 days with CMV highest serum DNA PCR 3969 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 2.59 and leukocyte count was 5.1 with negative SARS-CoV-2 antibody test. Therapy included reduction of immunosuppression, intravenous ganciclovir followed by 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. US-MODERNATX, INC.-MOD-2022-645823:Same Article, 67 yrs, Male US-MODERNATX, INC.-MOD-2022-645605:Same Article, 63 yrs, Male US-MODERNATX, INC.-MOD-2022-645826:Same Article, 42 yrs, Male US-MODERNATX, INC.-MOD-2022-645824:Same Article, 70 yrs, Female US-MODERNATX, INC.-MOD-2022-645824:Same Article, 56 yrs, Female US-MODERNATX, INC.-MOD-2022-645605:Same Article, 56 yrs, female