MYOCARDITIS; CHILLS; MYALGIAS; This spontaneous report was received from literature: Temporal association between the COVID-19 Ad26.COV2.S vaccine and acutemyocarditis: A case report and literature review. Cardiovascular Revascularization Medicine. This report concerned a 33 year old male. The patient's height, and weight were not reported. The patient's concurrent conditions included: asthma, and obstructive sleep apnea, and other pre-existing medical conditions included: The patient was previously healthy, had no known cardiac history. The patient did not have any known allergies, and he was up-to-date with all standard vaccinations with no prior history of adverse reactions. The patient denied any sick contacts or exposure to COVID-19 patients in the weeks prior to vaccination or travel. The patient received covid-19 vaccine ad26.cov2.s (suspension for injection, route of admin not reported, batch number: Unknown) dose, start therapy date were not reported, 1 total administered for prophylactic vaccination. The batch number was not reported and has been requested. No concomitant medications were reported.  On unspecified date, two days after vaccination the patient went to the emergency department with acute onset substernal chest pain. The patient initially noted myalgias and chills which resolved 24 hours following vaccination. This was followed by a constant, retrosternal, non-radiating, non-exertional chest pain. The pain was not positional, pleuritic, nor exertional. Patient was hospitalized on unspecified date. Upon admission, the patient was hemodynamically stable and afebrile. Laboratory data included: Electrocardiogram (ECG) showed normal sinus rhythm with normal intervals. Laboratory tests were remarkable for high-sensitivity (hs) troponin T 0.041 ng/mL (Normal range less than 0.014 ng/mL). The complete blood cell count with differential was normal and C reactive protein was 40.4 mg/L (Normal range 3.0 mg/L). Over the course of 24 hours, the troponin peaked to 10.2 ng/mL. A gadolinium enhanced cardiac magnetic resonance imaging showed a small focal area of myocarditis in the mid to apical lateral region of the left ventricle with a scar size of 2 percent. Overall, systolic function of the left ventricle was normal with no hypokinesis noted. The myocarditis was presumed to be due to the vaccine administered due to the strong chronological association. The patient was treated symptomatically, and he endorsed significant improvement in his symptoms. The patient was discharged home in stable condition with close follow-up. The action taken with covid-19 vaccine ad26.cov2.s was not applicable. The patient recovered from chills, and myalgias, and was recovering from myocarditis. Authors concluded that, the case highlighted the second possible case of vaccine induced myocarditis in an individual following administration of the Janssen vaccine. Authors believed that though they might see more cases of myocarditis following vaccination as millions were vaccinated worldwide, it was still a rare phenomenon for which the benefits of the vaccines far outweigh the risks. This report was serious (Hospitalization Caused / Prolonged).; Sender's Comments: V0: 20210839098- JANSSEN COVID-19 VACCINE Ad26.COV2.S- Myocarditis. This event is considered unassessable. The event has a compatible/suggestive temporal relationship, is unlabeled, and has unknown scientific plausibility. There is no information on any other factors potentially associated with the event.