Appendicitis; felt faint; bit of a headache; Difficulty breathing; Chest tightness; Feeling hot; Flushing; Prickling/Tingling; ears were ringing; almost passed out; Irregular heart rate/palpitations/her heart was pounding; Drop in blood Pressure; the patient felt really weird when the first shot was injected into her for about 40 minutes; the patient felt some pain around the injection site; This spontaneous case was reported by a consumer and describes the occurrence of APPENDICITIS (Appendicitis) in a 29-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 025C21A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Concurrent medical conditions included Irritable bowel syndrome, Anxiety, Blood pressure high, Seasonal allergy (running nose, watery eyes, stuffy nose, itching, sneezing, ect), Food allergy (Diarrhea, abdominal discomfort, gas, pain during digestion), Milk allergy (Symptoms of lactose intolerance. However, cheese and less does not affect patient.), Obesity and Pain. Concomitant products included PARACETAMOL (TYLENOL) for Pain.    On 09-May-2021 at 11:00 AM, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 09-May-2021, the patient experienced PALPITATIONS (Irregular heart rate/palpitations/her heart was pounding) and FEELING ABNORMAL (the patient felt really weird when the first shot was injected into her for about 40 minutes). 09-May-2021, the patient experienced BLOOD PRESSURE DECREASED (Drop in blood Pressure). In May 2021, the patient experienced VACCINATION SITE PAIN (the patient felt some pain around the injection site). On 02-Jun-2021, the patient experienced DYSPNOEA (Difficulty breathing), CHEST DISCOMFORT (Chest tightness), FEELING HOT (Feeling hot), FLUSHING (Flushing) and PARAESTHESIA (Prickling/Tingling). On 03-Jun-2021, the patient experienced APPENDICITIS (Appendicitis) (seriousness criteria hospitalization and medically significant). In June 2021, the patient experienced PRESYNCOPE (almost passed out) and TINNITUS (ears were ringing). On an unknown date, the patient experienced DIZZINESS (felt faint) and HEADACHE (bit of a headache). The patient was hospitalized on sometime in June 2021 due to APPENDICITIS. The patient was treated with Surgery (Apendicectomy) for Appendicitis. On 09-May-2021, BLOOD PRESSURE DECREASED (Drop in blood Pressure) had resolved. On 04-Jun-2021, APPENDICITIS (Appendicitis), PALPITATIONS (Irregular heart rate/palpitations/her heart was pounding), DYSPNOEA (Difficulty breathing), CHEST DISCOMFORT (Chest tightness), FEELING HOT (Feeling hot) and FLUSHING (Flushing) had resolved, PARAESTHESIA (Prickling/Tingling) outcome was unknown. At the time of the report, PRESYNCOPE (almost passed out), FEELING ABNORMAL (the patient felt really weird when the first shot was injected into her for about 40 minutes), DIZZINESS (felt faint), TINNITUS (ears were ringing) and HEADACHE (bit of a headache) outcome was unknown and VACCINATION SITE PAIN (the patient felt some pain around the injection site) had resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 09-May-2021, Blood pressure measurement: drop (Low) Drop in Blood Pressure. On an unknown date, Blood pressure measurement: little low (Low) little low.     mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosing remained unchanged.   For mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular), the reporter considered APPENDICITIS (Appendicitis) and BLOOD PRESSURE DECREASED (Drop in blood Pressure) to be possibly related. No further causality assessments were provided for PRESYNCOPE (almost passed out), PALPITATIONS (Irregular heart rate/palpitations/her heart was pounding), DYSPNOEA (Difficulty breathing), CHEST DISCOMFORT (Chest tightness), FEELING HOT (Feeling hot), FLUSHING (Flushing), PARAESTHESIA (Prickling/Tingling), FEELING ABNORMAL (the patient felt really weird when the first shot was injected into her for about 40 minutes), DIZZINESS (felt faint), TINNITUS (ears were ringing), VACCINATION SITE PAIN (the patient felt some pain around the injection site) and HEADACHE (bit of a headache).    Treatment information was not provided. The patient's body felt like it was going into red alert mode; like it did not like what was in the shot.  She felt faint, so the pharmacist took her blood pressure (which was usually on the higher side, because of her weight) and it was super low. Again after 15 minutes, bp was checked. It was a little low, but it was okay for her to go home. She felt some pain around the injection site for the next few days and had a bit of a headache, but that was it. When the patient was taking a shower on 02-Jun-2021, her right lower abdomen started hurting bad. Then that night when she got up to use the bathroom, it hurt so bad that her ears were ringing, and she almost passed out. The morning of 03-Jun-2021, her husband took her to the emergency room, and she was informed that she had appendicitis and it was needed to perform emergency surgery to remove it.  Company comment: This case concerns a 29-year-old female patient with no previous relevant medical history, who experienced the unexpected serious event/AESI of Appendicitis and other non serious events after Spikevax (mRNA- 1273 vaccine / Moderna COVID-19 Vaccine). The event occurred approximately 25 days after the first dose of Spikevax. The rechallenge for the event Appendicitis is not applicable since appendicectomy was performed. The benefit-risk relationship of Spikevax vaccine is not affected by this report   This case was linked to MOD-2021-354676 (Patient Link).   Most recent FOLLOW-UP information incorporated above includes: On 14-Jun-2021: The follow up document was received from the initial reporter: New event blood pressure drop and lab data were added. On 17-Oct-2021: Follow up document received and patient information, allergic reaction, medical history, suspect product batch/lot number, concomitant medication and new events added: palpitations, dyspnoea, chest discomfort, feeling hot, flushing, presyncope, feeling abnormal, dizziness, tinnitus, headache, vaccination site pain.; Sender's Comments: This case concerns a 29-year-old female patient with no previous relevant medical history, who experienced the unexpected serious event/AESI of Appendicitis and other non serious events after Spikevax (mRNA- 1273 vaccine / Moderna COVID-19 Vaccine). The event occurred approximately 25 days after the first dose of Spikevax. The rechallenge for the event Appendicitis is not applicable since appendicectomy was performed. The benefit-risk relationship of Spikevax vaccine is not affected by this report