Information received from the review of scientific literature on 02JUL2018.  This is case 4 of 6 (18000138LT, 18000139LT,18000140LT, 21000041LT,18000142LT, 18000143LT) Reference:   The article notes a 22-year-old active duty male who presented to the ED with aching centrally located chest pain approximately 9 days after receiving ACAM2000. His chest pain started earlier that morning, and was non-pleuritic, non-positional, non-exertional, and not radiating. The patient had no personal or family history of cardiac disease. His ECG showed sinus bradycardia at 53 bpm but was otherwise normal. A chest x-ray showed no acute cardiopulmonary disease. A troponin-I was elevated at 2.12. The case was discussed with Cardiology from an outside hospital and the patient was transferred for further care and evaluation of myopericarditis. As an inpatient, he had a normal cardiac catheterization and echocardiogram. After discharge, the patient was placed on a medical profile, made non-deployable, and was to be followed by cardiology as an outpatient. The patient's outcome was not reported in the article.   Additional information has been requested.  Follow up information was obtained on 04APR2021 during a review of scientific literature: personnel -2018.   2021, (MAR15) [cited 2021 Apr 04] 1-7.   This is case 2 of 5 reported cases within the article: (cross reference: 18000140LT, 18000141LT, 18000142LT, and 18000143LT).   The additional information received on 04APR2021 included: additional laboratory values, diagnosis and outcome information.  The patient was reported to be a 22 year old healthy male who received a primary dose of ACAM2000 in April 2018 and was subsequently diagnosed with probably myopericarditis. Additional symptoms reported included: shortness of breath, diaphoresis, dizziness, chills and fever. Additional significant laboratory findings included HSV 1 (Glycoprotein G Ab IgG): Positive, Epstein Barr Virus Capsid Ab IgG: Positive; Epstein-Barr Virus Nuclear Ab IgG: Positive. For other tests with negative results please refer to relevant Lab section. The patient received follow-up care with a cardiologist for 6 months and serial cardiac imaging. He was placed on limited duty with no exercise for 6 weeks and a non-deployable status for at least 6 months. He was followed by a cardiologist until complete recovery at between 3 and 9 months.  The authors concluded that there was no significant difference observed between the rate seen and the published rates that occurred during the clinical trials. The available evidence suggested that the 5 cases were not an unexpected elevation in the rate of the disease or condition, but rather a predictable number of myopericarditis cases proportional to the increased number of vaccinations performed during a short period of time.  Company comment: This report originated from a literature article describing myopericarditis following smallpox vaccination.  The report of myopericarditis is considered a medically significant event.  The event of sinus bradycardia is not a common feature of myopericarditis, but may possibly be related to the diagnosis.  The remaining reported events and time interval between immunization and onset are consistent with well described myocarditis/pericarditis known to follow ACAM2000, smallpox (vaccinia) immunization, therefore the causal relationship to ACAM2000 is considered related. The Information received on 04APR2021 does not change the previous assessment. Additional symptoms associated with myocarditis are not entered as points to consider.; Sender's Comments: Company comment: This report originated from a literature article describing myopericarditis following smallpox vaccination.  The report of myopericarditis is considered a medically significant event.  The event of sinus bradycardia is not a common feature of myopericarditis, but may possibly be related to the diagnosis.  The remaining reported events and time interval between immunization and onset are consistent with well described myocarditis/pericarditis known to follow ACAM2000, smallpox (vaccinia) immunization, therefore the causal relationship to ACAM2000 is considered related. The Information received on 04APR2021 does not change the previous assessment. Additional symptoms associated with myocarditis are not entered as points to consider.