Patient developed proximal bilateral leg weakness in both legs/more worse in the right leg; Light headedness/dizziness; Dry heaves; Right arm was itchy, swollen and warm at the injection site; Right arm was itchy, swollen and warm at the injection site/ over the next several days right arm became increasingly swollen/over the next several days right arm became increasingly itchy; Right arm was itchy, swollen and warm at the injection site/ over the next several days right arm became increasingly swollen/over the next several days right arm became increasingly itchy; Nausea; Headaches; Developed nodules in right let/developed 3 to 4 subcutaneous nodules about 1/2 to 1 cm in size in right let; Nodules tender; Nodules itchy; The patient developed a large right supraclavicular node; This spontaneous case was reported by a physician and describes the occurrence of SKIN MASS (Developed nodules in right let/developed 3 to 4 subcutaneous nodules about 1/2 to 1 cm in size in right let), NODULE (Nodules tender), PRURITUS (Nodules itchy), MUSCULAR WEAKNESS (Patient developed proximal bilateral leg weakness in both legs/more worse in the right leg) and DIZZINESS (Light headedness/dizziness) in a female patient of an unknown age who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 036A21A and 030M20A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Concurrent medical conditions included Chronic lymphatic leukemia (CLL not under treatment). Concomitant products included LOSARTAN, METOPROLOL SUCCINATE and MULTIVITAMIN [VITAMINS NOS] for an unknown indication.   On 03-Feb-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 03-Mar-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On 04-Mar-2021, the patient experienced DIZZINESS (Light headedness/dizziness), RETCHING (Dry heaves), VACCINATION SITE WARMTH (Right arm was itchy, swollen and warm at the injection site), VACCINATION SITE PRURITUS (Right arm was itchy, swollen and warm at the injection site/ over the next several days right arm became increasingly swollen/over the next several days right arm became increasingly itchy), NAUSEA (Nausea) and HEADACHE (Headaches). 04-Mar-2021, the patient experienced VACCINATION SITE SWELLING (Right arm was itchy, swollen and warm at the injection site/ over the next several days right arm became increasingly swollen/over the next several days right arm became increasingly itchy). In March 2021, the patient experienced SKIN MASS (Developed nodules in right let/developed 3 to 4 subcutaneous nodules about 1/2 to 1 cm in size in right let), NODULE (Nodules tender), PRURITUS (Nodules itchy) and LYMPHADENOPATHY (The patient developed a large right supraclavicular node). On an unknown date, the patient experienced MUSCULAR WEAKNESS (Patient developed proximal bilateral leg weakness in both legs/more worse in the right leg). On 06-Mar-2021, DIZZINESS (Light headedness/dizziness), RETCHING (Dry heaves), VACCINATION SITE WARMTH (Right arm was itchy, swollen and warm at the injection site), VACCINATION SITE PRURITUS (Right arm was itchy, swollen and warm at the injection site/ over the next several days right arm became increasingly swollen/over the next several days right arm became increasingly itchy), NAUSEA (Nausea) and HEADACHE (Headaches) had resolved. At the time of the report, SKIN MASS (Developed nodules in right let/developed 3 to 4 subcutaneous nodules about 1/2 to 1 cm in size in right let), NODULE (Nodules tender), PRURITUS (Nodules itchy) and LYMPHADENOPATHY (The patient developed a large right supraclavicular node) outcome was unknown and MUSCULAR WEAKNESS (Patient developed proximal bilateral leg weakness in both legs/more worse in the right leg) and VACCINATION SITE SWELLING (Right arm was itchy, swollen and warm at the injection site/ over the next several days right arm became increasingly swollen/over the next several days right arm became increasingly itchy) was resolving.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): In May 2021, Antibody test: normal (normal) Patient had demonstrable antibodies.     For mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular), the reporter considered SKIN MASS (Developed nodules in right let/developed 3 to 4 subcutaneous nodules about 1/2 to 1 cm in size in right let), NODULE (Nodules tender), PRURITUS (Nodules itchy), MUSCULAR WEAKNESS (Patient developed proximal bilateral leg weakness in both legs/more worse in the right leg), DIZZINESS (Light headedness/dizziness), RETCHING (Dry heaves), VACCINATION SITE WARMTH (Right arm was itchy, swollen and warm at the injection site), VACCINATION SITE PRURITUS (Right arm was itchy, swollen and warm at the injection site/ over the next several days right arm became increasingly swollen/over the next several days right arm became increasingly itchy), LYMPHADENOPATHY (The patient developed a large right supraclavicular node), VACCINATION SITE SWELLING (Right arm was itchy, swollen and warm at the injection site/ over the next several days right arm became increasingly swollen/over the next several days right arm became increasingly itchy), NAUSEA (Nausea) and HEADACHE (Headaches) to be probably related.    No treatment information was provided.