The swelling occurred in both in her right and left elbows; Both arms also have swelling on the outer side of the divet of the elbow. The swelling was the diameter of a golf ball and stuck out about 1 centimeter from the arm; running a low grade fever ever since she received the booster dose; Interchange of vaccine products; patient was dizzy for 7 weeks after getting the booster dose; This spontaneous case was reported by a consumer and describes the occurrence of JOINT SWELLING (The swelling occurred in both in her right and left elbows) in a 55-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 029H21B) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Previously administered products included for Product used for unknown indication: pfizer vaccine and pfizer vaccine. Past adverse reactions to the above products included No adverse event with pfizer vaccine and pfizer vaccine. Concurrent medical conditions included Autoimmune disorder, Hashimoto's disease, Chronic fatigue syndrome and Lyme disease (Lyme disease neurological involvement).    On 08-Dec-2021, the patient received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 08-Dec-2021, the patient experienced PYREXIA (running a low grade fever ever since she received the booster dose) and INTERCHANGE OF VACCINE PRODUCTS (Interchange of vaccine products). In December 2021, the patient experienced DIZZINESS (patient was dizzy for 7 weeks after getting the booster dose). On 29-Dec-2021, the patient experienced JOINT SWELLING (The swelling occurred in both in her right and left elbows) (seriousness criterion medically significant) and PERIPHERAL SWELLING (Both arms also have swelling on the outer side of the divet of the elbow. The swelling was the diameter of a golf ball and stuck out about 1 centimeter from the arm). On 08-Dec-2021, INTERCHANGE OF VACCINE PRODUCTS (Interchange of vaccine products) had resolved. In January 2022, DIZZINESS (patient was dizzy for 7 weeks after getting the booster dose) had resolved. At the time of the report, JOINT SWELLING (The swelling occurred in both in her right and left elbows) and PERIPHERAL SWELLING (Both arms also have swelling on the outer side of the divet of the elbow. The swelling was the diameter of a golf ball and stuck out about 1 centimeter from the arm) outcome was unknown and PYREXIA (running a low grade fever ever since she received the booster dose) had not resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Blood test: normal (normal) normal. On an unknown date, Ultrasound scan: normal (normal) normal.         The patient had a Moderna Booster dose on 08-Dec-2021 following her primary series of the Pfizer vaccine. On 29-DEC-2021 the patient first noticed a swelling on the inside of her right elbow. The swelling occurred on the body side of the divet of the elbow. A few hours later swelling started on the left elbow. The patient believed that the swelling was linked to the booster dose. The patients Orthopedics surgeon believed that the swelling was connected to the Moderna booster shot.  No Concomitant medications were reported. No treatment medications were reported.  Company comment.  This spontaneous case concerns a 55  year  old, female patient with relevant medical history of Lyme disease, who experienced the unexpected serious important medical event of joint swelling. Since the patient received the booster dose of mRNA-1273 vaccine, she experienced low graded fever. Three weeks later, she first noticed swelling on her right elbow, and a few hours later swelling started on the opposite side. Both arms also were swelling. The patient consulted an orthopedic surgeon, blood tests and ultrasound were performed with normal result. It is mentioned she had dizziness during 7 weeks after mRNA  1273 dose. No treatment is reported. The mentioned medical history could be a confounder. The patient previously had two doses of Pfizer COVID vaccine. The benefit-risk relationship of mRNA-1273 is not affected by this report.; Sender's Comments: This spontaneous case concerns a 55  year  old, female patient with relevant medical history of Lyme disease, who experienced the unexpected serious important medical event of joint swelling. Since the patient received the booster dose of mRNA-1273 vaccine, she experienced low graded fever. Three weeks later, she first noticed swelling on her right elbow, and a few hours later swelling started on the opposite side. Both arms also were swelling. The patient consulted an orthopedic surgeon, blood tests and ultrasound were performed with normal result. It is mentioned she had dizziness during 7 weeks after mRNA  1273 dose. No treatment is reported. The mentioned medical history could be a confounder. The patient previously had two doses of Pfizer COVID vaccine. The benefit-risk relationship of mRNA-1273 is not affected by this report.