Smallpox vaccination-associated myopericarditis / Probable Myocarditis; Mild PR depression in lead I; C-reactive protein elevated; Non-deployable; Information received from the review of scientific literature on 02JUL2018.  This is case 3 of 6 (18000138LT, 18000139LT,18000140LT, 18000141LT,18000142LT, 18000143LT)  The article notes a 25-year-old active duty male who presented to the ED with one day of achy chest pain 11 days after receiving ACAM2000. His chest pain was gradual in onset, centrally located, non-exertional, non-positional and without any radiation. The patient had no significant family history of cardiac disease. The ECG showed, ST depression in lead aVL and mild PR depression/ST elevations in lead I. These were new findings compared to a previous ECG. His troponin-I was elevated at 2.24, and his C-reactive protein was elevated at 1.49. No acute cardiopulmonary disease was seen in chest x-ray, and a bedside transthoracic echocardiogram showed no pericardial effusion. Cardiology was consulted from an outside hospital and the patient was transferred for further treatment of myocarditis. After discharge, the patient was placed on ibuprofen and instructed to follow-up with his primary care physician. At follow-up, he was placed on a 3-month medical profile and made non-deployable. He was to be followed by cardiology as an outpatient. The patient's outcome was not reported in the article.   Follow up information was obtained on 04APR2021 during a review of scientific literature:  This is case 4 of 5 reported cases within the article: (cross reference: 21000041LT, 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 25-year-old healthy male who received a primary dose of ACAM2000 in April 2018 and was subsequently diagnosed with probable myopericarditis. 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 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. Information received on 04APR2021 does not change the previous assessment, Symptoms associated with myocarditis are not entered as adverse event as per MedDRA 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 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. Information received on 04APR2021 does not change the previous assessment, Symptoms associated with myocarditis are not entered as adverse event as per MedDRA points to consider.