Acute chest syndrome; Patient says that he feels chest pain/Fleeting pain in his chest/Acute Pain lasting 1 minute; Lethargy; Palpitations One occurrence. Did not last long. Fleeting.; Feels very sick since receiving the vaccine; Feels like he has inflammation; Heart feels weird/chest discomfort; Experiencing itchy nipples on his chest; This spontaneous case was reported by a consumer and describes the occurrence of ACUTE CHEST SYNDROME (Acute chest syndrome) in a 50-year-old male patient who received mRNA-1273 (Spikevax) (batch no. 027L21A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     The patient's past medical history included COVID-19 on 11-Mar-2021.    On 01-Mar-2022, the patient received first dose of mRNA-1273 (Spikevax) (unknown route) 1 dosage form. On 01-Mar-2022, the patient experienced MALAISE (Feels very sick since receiving the vaccine). On 04-Mar-2022, the patient experienced ACUTE CHEST SYNDROME (Acute chest syndrome) (seriousness criterion medically significant), CHEST PAIN (Patient says that he feels chest pain/Fleeting pain in his chest/Acute Pain lasting 1 minute), LETHARGY (Lethargy) and PALPITATIONS (Palpitations One occurrence. Did not last long. Fleeting.). In March 2022, the patient experienced INFLAMMATION (Feels like he has inflammation), CHEST DISCOMFORT (Heart feels weird/chest discomfort) and PRURITUS (Experiencing itchy nipples on his chest). In March 2022, PALPITATIONS (Palpitations One occurrence. Did not last long. Fleeting.) had resolved. At the time of the report, ACUTE CHEST SYNDROME (Acute chest syndrome), MALAISE (Feels very sick since receiving the vaccine), INFLAMMATION (Feels like he has inflammation), CHEST DISCOMFORT (Heart feels weird/chest discomfort), PRURITUS (Experiencing itchy nipples on his chest), CHEST PAIN (Patient says that he feels chest pain/Fleeting pain in his chest/Acute Pain lasting 1 minute) and LETHARGY (Lethargy) had not resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 15-Mar-2021, SARS-CoV-2 test: positive (Positive) Positive.     The action taken with mRNA-1273 (Spikevax) (Unknown) was unknown.   For mRNA-1273 (Spikevax) (Unknown), the reporter did not provide any causality assessments.   The concomitant medication was not reported.  There was no history of Myocarditis/Pericarditis.  The treatment medication was not reported.  COMPANY COMMENT : This spontaneous case concerns a 50 -year-old male patient with no relevant medical history, who experienced the unexpected serious (seriousness criterion medically significant) event of acute chest syndrome, which occurred 3 days after receiving first dose of mRNA- 1273 vaccine. It is reported SARS-CoV-2 test is positive on 15-Mar-2021. The benefit-risk relationship of mRNA-1273 Vaccine is not affected by this report.   Most recent FOLLOW-UP information incorporated above includes: On 11-Mar-2022: Follow-up information received contains no new information.; Sender's Comments: This spontaneous case concerns a 50 -year-old male patient with no relevant medical history, who experienced the unexpected serious (seriousness criterion medically significant) event of acute chest syndrome, which occurred 3 days after receiving first dose of mRNA- 1273 vaccine. It is reported SARS-CoV-2 test is positive on 15-Mar-2021. The benefit-risk relationship of mRNA-1273 Vaccine is not affected by this report.