Pericarditis; This literature-non-study case was reported in a literature article and describes the occurrence of PERICARDITIS (Pericarditis) in a  patient of an unknown age and gender who received mRNA-1273 (Spikevax) for COVID-19 prophylaxis.        No Medical History information was reported.    On an unknown date, the patient received first dose of mRNA-1273 (Spikevax) (unknown route) 1 dosage form. On an unknown date, the patient experienced PERICARDITIS (Pericarditis) (seriousness criterion medically significant). At the time of the report, PERICARDITIS (Pericarditis) had resolved.        The action taken with mRNA-1273 (Spikevax) (Unknown) was unknown.   For mRNA-1273 (Spikevax) (Unknown), the reporter considered PERICARDITIS (Pericarditis) to be related.    This case was for patient no.1, who experienced pericarditis after first dose of Moderna vaccine.  No concomitant or treatment medications were reported.   This study is based on a cohort evaluation of all adults administered =1 mRNA COVID-19 vaccine, including boosters, in the Administration between 14 December 2020 and 9 October 2022. From 14 December 2020 to 9 October 2022, 2 184 449 first and 2 036 948 second doses of mRNA-1273 (Moderna) were administered. In addition, 1 156 160 mRNA-1273 booster doses were administered. Among vaccine recipients in our cohort aged 1839 (predominately male, as expected-based cohort), estimated incidence rates of confirmed myocarditis/pericarditis ranged from 0.46 cases per million (for Moderna dose 1, all ages) to 19.76 (Pfizer dose 2, ages 1839). Of the 178 potential safety events identified by the Agency, only 33 were ultimately confirmed following an mRNA vaccine. Potential cases were ruled out after chart review for various reasons.  In summary, the incidence of myocarditis or pericarditis in patients was low across >10 million doses of mRNA COVID-19 vaccines (primary or booster doses) administered.   This case was linked to US-MODERNATX, INC.-MOD-2023-734771, US-MODERNATX, INC.-MOD-2023-734772, US-MODERNATX, INC.-MOD-2023-734779, US-MODERNATX, INC.-MOD-2023-734781, US-MODERNATX, INC.-MOD-2023-734783, US-MODERNATX, INC.-MOD-2023-734784, US-MODERNATX, INC.-MOD-2023-734787, US-MODERNATX, INC.-MOD-2023-734788, US-MODERNATX, INC.-MOD-2023-734790, US-MODERNATX, INC.-MOD-2023-734793, US-MODERNATX, INC.-MOD-2023-734816, US-MODERNATX, INC.-MOD-2023-734817, US-MODERNATX, INC.-MOD-2023-734936 (Linked Report).  Company comment: This is a literature non-study case concerning a patient of an unknown age and gender with no medical history reported, who experienced the expected serious medically significant event Pericarditis. The event occurred after receiving the first dose of mRNA-1273 vaccine (event and vaccine dates were not provided). Concomitant and treatment medications were not reported. The outcome of the event was reported as resolved. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.   Most recent FOLLOW-UP information incorporated above includes: On 27-Jul-2023: Live follow up received by safety on 27-JUL-2023 has email with Agency that contains significant information: Reporter information, literature information, suspect information and event details were updated.; Sender's Comments: Company comment: This is a literature non-study case concerning a patient of an unknown age and gender with no medical history reported, who experienced the expected serious medically significant event Pericarditis. The event occurred after receiving the first dose of mRNA-1273 vaccine (event and vaccine dates were not provided). Concomitant and treatment medications were not reported. The outcome of the event was reported as resolved. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report. US-MODERNATX, INC.-MOD-2023-734771:Same literature (Master case) US-MODERNATX, INC.-MOD-2023-734779:Same literature (Master case) US-MODERNATX, INC.-MOD-2023-734772:Same literature (Master case) US-MODERNATX, INC.-MOD-2023-734816:Same literature (Master case) US-MODERNATX, INC.-MOD-2023-734784:Same literature (Master case) US-MODERNATX, INC.-MOD-2023-734817:Same literature (Master case) US-MODERNATX, INC.-MOD-2023-734783:Same literature (Master case) US-MODERNATX, INC.-MOD-2023-734787:Same literature (Master case) US-MODERNATX, INC.-MOD-2023-734793:Same literature (Master case) US-MODERNATX, INC.-MOD-2023-734790:Same literature (Master case) US-MODERNATX, INC.-MOD-2023-734788:Same literature (Master case) US-MODERNATX, INC.-MOD-2023-734781:Same literature (Master case) US-MODERNATX, INC.-MOD-2023-734936:Same literature (Master case)