CMV DNAemia noted after COVID-19 mRNA vaccination in the thoracic organ transplant recipients; This is a literature report.  The purpose of the study was to study cases of Cytomegalovirus (CMV) DNAemia noted after COVID-19 mRNA vaccination in the thoracic organ transplant recipients. Between March 1, 2021, and June 30, 2021, the authors identified 7 cases of CMV infection in thoracic organ transplant recipients within 30 days of COVID-19 mRNA vaccination. Descriptive statistics was used to study these cases. Of the patients, 3 were lung recipients, 3 were heart recipients while one was a dual heart-kidney recipient. Three patients received the mRNA-1273 (Moderna) vaccine while others received the BNT162b2 (Pfizer) vaccine. Age ranged from 42 to 73 years. Two of the lung transplant recipients and one heart recipient were CMV high-risk status (Donor+/Recipient-), while the others were recipient-seropositive for CMV. The median time to PCR detection of CMV DNAemia from the second dose of mRNA vaccine was 16 days with a range of 4 days to 30 days. None of these recipients had post-transplant CMV infection detected previously. All patients were off antiviral prophylaxis and on their standard immunosuppressive regimen at the time of vaccination. Symptoms were variable but ranged from asymptomatic to acute respiratory failure. However, all patients had resolution of CMV DNAemia by the censor date with a range of 7 days to 45 days. Therapy included reduction of immunosuppression, intravenous ganciclovir, and oral valganciclovir. The median peak CMV DNA PCR in the cohort was 15,900 IU/ml with a range of 272 IU/ml to 175,973 IU/ml. None of the recipients developed IgG antibodies to SARS-CoV-2 in response to vaccination. There were no documented cases of COVID-19 in these transplant recipients. CMV DNAemia after COVID-19 mRNA vaccination in solid organ transplant recipients may be an under-recognized phenomenon. Although the risk-benefit assessment strongly favors COVID-19 vaccination, due to the greater risk of adverse events with COVID-19 infection care teams should consider active monitoring for CMV disease activity in these patients. In some cases, CMV prophylaxis may be warranted depending on patients' risk profile. The findings warrant study in a larger prospective study.  A patient (no qualifiers provided) received BNT162b2 (BNT162B2), as dose 1, single (Batch/Lot number: unknown) and as dose 2, single (Batch/Lot number: unknown) for covid-19 immunisation. The patient's relevant medical history included: "thoracic organ transplant" (unspecified if ongoing). The patient's concomitant medications were not reported. The following information was reported: CYTOMEGALOVIRUS VIRAEMIA (medically significant), outcome "recovered", described as "CMV DNAemia noted after COVID-19 mRNA vaccination in the thoracic organ transplant recipients". The patients had resolution of CMV DNAemia by the censor date with a range of 7 days to 45 days. Therapy included reduction of immunosuppression, intravenous ganciclovir, and oral valganciclovir. The patient underwent the following laboratory tests and procedures: CMV DNA PCR (272-175973 IU/ml): Unknown results; IgG antibodies to SARS-CoV-2: None. Therapeutic measures were taken as a result of cytomegalovirus viraemia.  No follow-up attempts are possible; information about lot/batch number cannot be obtained. No further information is expected.; Sender's Comments: A possibly contributory role of BNT162B2 in triggering the onset of CMV DNAemia cannot be fully excluded, considering the temporal relationship.  More immunological and biomolecular evidence would be needed to explore the plausible physiopathologic mechanism between the vaccination and the event occurrence.  The impact of this report on the benefit/risk profile of the Pfizer product is evaluated as part of Pfizer procedures for safety evaluation, including the review and analysis of aggregate data for adverse events. Any safety concern identified as part of this review, as well as any appropriate action in response, will be promptly notified to Regulatory Authorities, Ethics Committees and Investigators, as appropriate,Linked Report(s) : US-PFIZER INC-202200591731 Same article/drug/event; different patient;US-PFIZER INC-202200591905 Same article/drug/event; different patient;US-PFIZER INC-202200591906 Same article/drug/event; different patient