Hypoglycemia/blood sugar dropped; Patient had received 3 doses of Pfizer COVID-19 vaccine prior to mRNA-1273 vaccination; COVID-19; This spontaneous case was reported by a patient family member or friend and describes the occurrence of HYPOGLYCAEMIA (Hypoglycemia/blood sugar dropped) in an 87-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 0651C21A/065K21A) for COVID-19 prophylaxis. The occurrence of additional non-serious events is detailed below.    Co-suspect products included non-company products TOZINAMERAN (PFIZER BIONTECH COVID-19 VACCINE) for an unknown indication and NIRMATRELVIR, RITONAVIR (PAXLOVID) tablet for COVID-19.    Patient was not diabetic.  The patient's past medical history included Insulinoma and Surgery (Surgery for insulinoma which is a begin tumor on the pancreas which causes the pancreas to secrete too much insulin. Took that off and didn't take much of the pancreas. Everything was clear and the biopsy was good Has been getting along fine since then.) in March 2022. Concomitant products included SIMVASTATIN for an unknown indication.   On 26-Feb-2021, the patient received first dose of TOZINAMERAN (PFIZER BIONTECH COVID-19 VACCINE) (unknown route) 1 dosage form. On 19-Mar-2021, received second dose of TOZINAMERAN (PFIZER BIONTECH COVID-19 VACCINE) (unknown route) dosage was changed to 1 dosage form. On 22-Dec-2021, received third dose of TOZINAMERAN (PFIZER BIONTECH COVID-19 VACCINE) (unknown route) dosage was changed to 1 dosage form. On 11-May-2022, the patient received fourth dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 30-Jul-2022, the patient started NIRMATRELVIR, RITONAVIR (PAXLOVID) (Oral) 3 dosage form twice a day. In July 2022, the patient experienced COVID-19 (COVID-19). On 09-Aug-2022,  after starting mRNA-1273 (Moderna COVID-19 Vaccine), the patient experienced HYPOGLYCAEMIA (Hypoglycemia/blood sugar dropped) (seriousness criterion hospitalization). On an unknown date, the patient experienced INTERCHANGE OF VACCINE PRODUCTS (Patient had received 3 doses of Pfizer COVID-19 vaccine prior to mRNA-1273 vaccination). The patient was hospitalized on 09-Aug-2022 due to HYPOGLYCAEMIA. At the time of the report, HYPOGLYCAEMIA (Hypoglycemia/blood sugar dropped) was resolving and COVID-19 (COVID-19) and INTERCHANGE OF VACCINE PRODUCTS (Patient had received 3 doses of Pfizer COVID-19 vaccine prior to mRNA-1273 vaccination) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): In July 2022, SARS-CoV-2 test: Positive. On 09-Aug-2022, Blood glucose: 29. On an unknown date, Biopsy pancreas: everything was clear and the biopsy was good.     For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter did not provide any causality assessments.   Patient doctor had him quit taking simvastatin while on Paxlovid because it's one of the drugs that interact with the Paxlovid.  It was reported that patient was using co-suspect drug paxlovid 3 pills in the morning and 3 at night; for five days by mouth.  Patient tested positive and was given Paxlovid. Finished Paxlovid a week ago today, 03Aug2022 and his blood sugar dropped, and he is in the hospital. Timing seems rather interesting that the Covid, Paxlovid, and then blood sugar drop when there hadn't been any problems with his blood sugar since March until now.  Patient was still hospitalized while the doctors try to figure out why and patient was on an IV that is stabilizing his blood sugar  Patient Outcome of Blood sugar is better now.  Company Comment :  This is a spontaneous case, reported by a patient family member or friend, concerning an 87-year-old male patient with relevant medical history of Insulinoma, who was hospitalized due to the unexpected serious event of Hypoglycaemia reported as blood sugar dropped, and unexpected non-serious adverse event of special interest COVID-19. The event COVID-19 supported by a positive SARS-CoV-2 test occurred approximately 2 months post mRNA-1273 vaccination, while the event Hypoglycaemia approximately 3 months after receiving a dose of mRNA-1273 as the fourth/booster dose of COVID-19 vaccine. Latency for the event COVID-19 cannot be properly assessed since event onset date was not provided. Patient had received 3 doses of Pfizer COVID-19 vaccine approximately 4 months and 2 weeks prior to mRNA-1273 vaccination (Interchange of vaccine products). It was reported that the patient had no diabetes and underwent surgical removal of insulinoma with no problems on blood sugar. Patient experienced COVID-19 infection and was treated with 5-day course of Paxlovid while on medication of simvastatin. Patient experienced hypoglycemia with blood glucose of 29, and was advised to discontinue taking simvastatin while on Paxlovid treatment due to drug-to-drug interaction. Patient was given unspecified IV medication that stabilized the blood sugar level. Outcome of the event COVID-19 was unknown, while the event Hypoglycaemia was resolving. The medical history of Insulinoma and drug to drug interaction of Paxlovid and simvastatin remain as confounders for the event Hypoglycaemia. The benefit-risk relationship of mRNA-1273 is not affected by this report.   Most recent FOLLOW-UP information incorporated above includes: On 12-Aug-2022: Additional information received on 12-Aug-2022 and updated Quality complaint no. in reference.; Sender's Comments: This is a spontaneous case, reported by a patient family member or friend, concerning an 87-year-old male patient with relevant medical history of Insulinoma, who was hospitalized due to the unexpected serious event of Hypoglycaemia reported as blood sugar dropped, and unexpected non-serious adverse event of special interest COVID-19. The event COVID-19 supported by a positive SARS-CoV-2 test occurred approximately 2 months post mRNA-1273 vaccination, while the event Hypoglycaemia approximately 3 months after receiving a dose of mRNA-1273 as the fourth/booster dose of COVID-19 vaccine. Latency for the event COVID-19 cannot be properly assessed since event onset date was not provided. Patient had received 3 doses of Pfizer COVID-19 vaccine approximately 4 months and 2 weeks prior to mRNA-1273 vaccination (Interchange of vaccine products). It was reported that the patient had no diabetes and underwent surgical removal of insulinoma with no problems on blood sugar. Patient experienced COVID-19 infection and was treated with 5-day course of Paxlovid while on medication of simvastatin. Patient experienced hypoglycemia with blood glucose of 29, and was advised to discontinue taking simvastatin while on Paxlovid treatment due to drug-to-drug interaction. Patient was given unspecified IV medication that stabilized the blood sugar level. Outcome of the event COVID-19 was unknown, while the event Hypoglycaemia was resolving. The medical history of Insulinoma and drug to drug interaction of Paxlovid and simvastatin remain as confounders for the event Hypoglycaemia. The benefit-risk relationship of mRNA-1273 is not affected by this report.