"blood clot or something" on her right leg; not being able to walk well; pain, swelling, redness on her leg; pain, swelling, redness on her leg; side effects; pain, swelling, redness on her leg/leg was bad it was more on the surface/symptoms, leg bothered a couple of months.; This spontaneous case was reported by a consumer and describes the occurrence of THROMBOSIS ("blood clot or something" on her right leg), GAIT DISTURBANCE (not being able to walk well), PERIPHERAL SWELLING (pain, swelling, redness on her leg), ERYTHEMA (pain, swelling, redness on her leg) and VACCINATION COMPLICATION (side effects) in a 76-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     No Medical History information was reported.    On 04-Oct-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 06-Oct-2021, the patient experienced THROMBOSIS ("blood clot or something" on her right leg), GAIT DISTURBANCE (not being able to walk well), PERIPHERAL SWELLING (pain, swelling, redness on her leg), ERYTHEMA (pain, swelling, redness on her leg), VACCINATION COMPLICATION (side effects) and PAIN IN EXTREMITY (pain, swelling, redness on her leg/leg was bad it was more on the surface/symptoms, leg bothered a couple of months.). At the time of the report, THROMBOSIS ("blood clot or something" on her right leg), GAIT DISTURBANCE (not being able to walk well), PERIPHERAL SWELLING (pain, swelling, redness on her leg), ERYTHEMA (pain, swelling, redness on her leg), VACCINATION COMPLICATION (side effects) and PAIN IN EXTREMITY (pain, swelling, redness on her leg/leg was bad it was more on the surface/symptoms, leg bothered a couple of months.) had resolved.        mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown) was withdrawn on an unknown date.       Concomitant information was reported as several different medication.  Patient only received 1 dose of the Moderna COVID19 vaccine. Patient did not received a vaccination card. Patient should have received her 2nd dose on Nov. Following vaccination 2 days later patient started to experience: symptoms. Patient stated that it was not a deep vain thing.   The symptoms started to happen so close to the vaccination that it made her believe that it was because of the vaccination and she never had something like that before.  Duration of the symptoms were reported as : "lasted weeks"   Patient reported that the symptoms were not ongoing.   Treatment information was not provided.  Patient wanted to know if someone never came back for their 2st dose of the Moderna COVID19 vaccine after receiving the 1st dose. Company comment:This spontaneous case concerns a 76-year-old, female patient with no reported medical history, who experienced the unexpected, non-serious AESI of Thrombosis. The event occurred 2 days after administration of second dose of mRNA-1273. It has been reported that following vaccination two days later patient started to experience symptoms, she claimed that it was not a deep vein thing, the symptoms reportedly lasted weeks, patient was scheduled to receive her second dose last November (Inappropriate schedule of product administration). The symptoms were claimed to have resolved.  The benefit-risk relationship of mRNA-1273 is not affected by this report.; Sender's Comments: This spontaneous case concerns a 76-year-old, female patient with no reported medical history, who experienced the unexpected, non-serious AESI of Thrombosis. The event occurred 2 days after administration of second dose of mRNA-1273. It has been reported that following vaccination two days later patient started to experience symptoms, she claimed that it was not a deep vein thing, the symptoms reportedly lasted weeks, patient was scheduled to receive her second dose last November (Inappropriate schedule of product administration). The symptoms were claimed to have resolved.  The benefit-risk relationship of mRNA-1273 is not affected by this report.