Weakness; Swelling in nerves around L5; inflammation in leg(new place) running down outside leg below knee; increased swelling in left leg from knee down to calf; This spontaneous case was reported by a patient (subsequently medically confirmed) and describes the occurrence of PERIPHERAL SWELLING (increased swelling in left leg from knee down to calf), ASTHENIA (Weakness), NEURITIS (Swelling in nerves around L5) and JOINT SWELLING (inflammation in leg(new place) running down outside leg below knee) in a 67-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 011M20A and 001B21A) for COVID-19 vaccination.     The patient's past medical history included DVT since an unknown date. Concurrent medical conditions included Shellfish allergy, Food allergy (lactose, wheat and mushroom), Drug allergy (Sulfa and gabapentin) and Iodine allergy. Concomitant products included APIXABAN (ELIQUIS) for Unilateral leg swelling, PROPRANOLOL, LEVOTHYROXINE SODIUM (SYNTHROID), NORTRIPTYLINE, RABEPRAZOLE SODIUM (ACIPHEX), FEXOFENADINE HYDROCHLORIDE (ALLEGRA), FUROSEMIDE, BETAMETHASONE and MONTELUKAST SODIUM (SINGULAIR) for an unknown indication.   On 08-Feb-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 12-Mar-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On 08-Feb-2021, the patient experienced PERIPHERAL SWELLING (increased swelling in left leg from knee down to calf). On an unknown date, the patient experienced ASTHENIA (Weakness), NEURITIS (Swelling in nerves around L5) and JOINT SWELLING (inflammation in leg(new place) running down outside leg below knee). At the time of the report, PERIPHERAL SWELLING (increased swelling in left leg from knee down to calf) had resolved and ASTHENIA (Weakness), NEURITIS (Swelling in nerves around L5) and JOINT SWELLING (inflammation in leg(new place) running down outside leg below knee) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 14-May-2021, Magnetic resonance imaging: (Inconclusive) Results are not updated.. On an unknown date, Ultrasound scan: (Inconclusive) Very long dot in left leg from groin to ankle which swelled and turned red. So, ultrasound was done. No clot action found but pain went on for few weeks..     mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) and mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown) dosing remained unchanged.       No treatment details were reported.  Event outcome for weakness, swelling in nerves at L5 and inflammation below knee was not reported.  Patient reported that weakness is a residual effect of leg swelling which led to inflammation in leg(new place) running down outside leg below knee and swelling in nerves in the back around L5.   This case was linked.   Most recent FOLLOW-UP information incorporated above includes: On 17-May-2021: This follow-up was received on 17-MAY-2021 which updated patient demographics, allergic conditions, lab data, concomitant medications, dose 2 details events(swelling in nerves and inflammation below knee) and  event outcome for peripheral swelling.