Appendicitis; Angioedema of the face; congestion; Joint pain; Nausea; Fatigue; fever; cardiac abnormalities; "blacked out"; Ulcers in/around the mouth; "zaps" all over her body and to her brain; overall body pain; Headaches; Chills; A spontaneous report was received from a healthcare professional concerning a 47-year-old female patient who received Moderna's COVID-19 vaccine (mRNA-1273) and experienced appendicitis, angioedema of the face, ulcer in/around the mouth, joint pain, zaps all over her body and to her brain, headaches, chills, nausea, fatigue, "blacked out" loss of consciousness, congestion, overall body pain, cardiac abnormalities.  The patient's medical history included Covid-19. No relevant concomitant medications were reported.   In March of 2020, the patient was first diagnosed with COVID-19. The patient reported she has since been considered a "long hauler" and has experienced various symptoms of the disease since that time.  On 26 Jan 2021, the patient received their first of two planned doses of mRNA-1273 ([LOT# 011J20A]) intramuscularly for prophylaxis of COVID-19 infection. After receiving the first dose of the vaccine the patient initially experienced joint pain and "zaps" all over her body and to her brain, headaches, chills and overall body pain.  On an unspecified date, after visiting her doctor, the patient was diagnosed with angioedema of the face. Treatment medication included 2 different unspecified antihistamines. Once that condition was remedied (date unspecified), the patient still experienced fatigue, nausea and congestion.   On 28 Jan 2021 the patient experienced swelling of the mouth and ulcers in and around the mouth.   On 29 Jan 2021, the patient experienced severe stomach pain and cramping as well as a fever that worsened through the night. Treatment included oxycodone hydrochloride.   On the morning of 29 Jan 2021, the patient was still experiencing abdominal pain and began vomiting. The pain was so much that the patient "blacked out" and was transported to the Emergency Room (ER). At the ER the patient experienced unspecified cardiac abnormalities. While in the ER, the patient was diagnosed with appendicitis and subsequently underwent an appendectomy.  On 30 Jan 2021, the patient was discharged from the ER and was still experienced nausea, fatigue and fever.  Action taken with mRNA-1273 in response to the events was not reported.  The event of appendicitis was considered recovered/resolved on 30 Jan 2021, the event of angioedema and "blacked out" were considered recovered/resolved (dates not reported). The events of nausea, fatigue, and fever were considered not recovered/not resolved. The event outcome for ulcers in/around the mouth, joint pain, "zaps" all over her body and to her brain, headaches, chills, congestion, overall body pain, and cardiac abnormalities was considered unknown.; Reporter's Comments: This case concerns a 47-year-old, female subject, with medical history of COVID-19 (Mar-2020), who experienced serious events of angioedema, LOC, and appendicitis. Based on the current available information and temporal association between the use of the product and the start date of the event, a causal relationship cannot be excluded. Based on the mechanism of action of mRNA-1273, the event of appendicitis is considered not related to the vaccine. Further information has been requested.