Acute rejection; SARS-CoV-2 infection; This literature-non-study case was reported in a literature article and describes the occurrence of TRANSPLANT REJECTION (Acute rejection) in a  patient of an unknown age and gender who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 prophylaxis. The occurrence of additional non-serious events is detailed below.    The patient's past medical history included Solid organ transplant.    On an unknown date, the patient received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. In 2021, the patient experienced TRANSPLANT REJECTION (Acute rejection) (seriousness criterion medically significant) and COVID-19 (SARS-CoV-2 infection). At the time of the report, TRANSPLANT REJECTION (Acute rejection) and COVID-19 (SARS-CoV-2 infection) outcome was unknown.        For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter did not provide any causality assessments.   Concomitant and treatment medications were not reported.  Case reports were requested between 7-Apr-2021 and 21-Jun-2021. Sixty-six cases of SARS-CoV-2 infection after vaccination in solid organ transplant recipients (SOTR) were collected.  Solid organ transplant recipients (SOTR) vaccinated against COVID-19 can still develop severe, and even critical, COVID-19 disease. Two doses of mRNA COVID-19 vaccine may be insufficient to protect against severe disease and mortality in SOTR.. Company comment-This literature-non-study case concerns a patient of unspecified age and gender with past medical history of Solid organ transplant reported, who experienced the unexpected serious (medically significant) event of Transplant rejection (reported as Acute rejection) on an unknown date after second dose of mRNA-1273 vaccine in covid-19 vaccination series. Patient also experienced unexpected non-serious event of COVID-19 on unknown date. No information on detailed clinical course, lab details, treatment received was available in the report. Outcome of the events was unknown at the time of report. Past medical history remains a confounder. Solid organ transplant recipients (SOTR) have diminished humoral immune responses to COVID-19 vaccination and higher rates of COVID infection than the general population. SOTR vaccinated against COVID-19 can still develop severe, and even critical, COVID-19 disease. Two doses of mRNA COVID-19 vaccine may be insufficient to protect against severe disease and mortality in SOTR. The benefit-risk relationship of mRNA-1273 is not affected by this report.; Sender's Comments: This literature-non-study case concerns a patient of unspecified age and gender with past medical history of Solid organ transplant reported, who experienced the unexpected serious (medically significant) event of Transplant rejection (reported as Acute rejection) on an unknown date after second dose of mRNA-1273 vaccine in covid-19 vaccination series. Patient also experienced unexpected non-serious event of COVID-19 on unknown date. No information on detailed clinical course, lab details, treatment received was available in the report. Outcome of the events was unknown at the time of report. Past medical history remains a confounder. Solid organ transplant recipients (SOTR) have diminished humoral immune responses to COVID-19 vaccination and higher rates of COVID infection than the general population. SOTR vaccinated against COVID-19 can still develop severe, and even critical, COVID-19 disease. Two doses of mRNA COVID-19 vaccine may be insufficient to protect against severe disease and mortality in SOTR. The benefit-risk relationship of mRNA-1273 is not affected by this report.