knees started swelling and became extremely weak with tendon pain; knees started swelling and became extremely weak with tendon pain; achy shoulders; stiff neck; shoulder weakness to the neck and upper arm down to his knees; slight headache; knee pain; fever running possibly closer to 99.5F; chills; arm soreness; This spontaneous case was reported by a consumer (subsequently medically confirmed) and describes the occurrence of MUSCULOSKELETAL STIFFNESS (stiff neck), MUSCULAR WEAKNESS (shoulder weakness to the neck and upper arm down to his knees), JOINT SWELLING (knees started swelling and became extremely weak with tendon pain), TENDON PAIN (knees started swelling and became extremely weak with tendon pain) and MYALGIA (achy shoulders) in a 73-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 014M20A and 013L20A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     No medical history was provided by the reporter.  Concomitant products included LOSARTAN for Blood pressure high, LACTOBACILLUS ACIDOPHILUS (FLORASTOR [LACTOBACILLUS ACIDOPHILUS]) for Diverticulosis, KETOCONAZOLE from 31-Dec-2018 to an unknown date for Folliculitis, TAMSULOSIN from 02-Apr-2014 to an unknown date for Urination difficulty, CYANOCOBALAMIN for an unknown indication.   On 25-Jan-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 25-Feb-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On 25-Feb-2021, the patient experienced CHILLS (chills) and PAIN IN EXTREMITY (arm soreness). On 26-Feb-2021, the patient experienced MUSCULOSKELETAL STIFFNESS (stiff neck), MUSCULAR WEAKNESS (shoulder weakness to the neck and upper arm down to his knees), MYALGIA (achy shoulders), HEADACHE (slight headache) and ARTHRALGIA (knee pain). 26-Feb-2021, the patient experienced PYREXIA (fever running possibly closer to 99.5F). On an unknown date, the patient experienced JOINT SWELLING (knees started swelling and became extremely weak with tendon pain) and TENDON PAIN (knees started swelling and became extremely weak with tendon pain). On 26-Feb-2021, CHILLS (chills) had resolved. On 01-Apr-2021, MUSCULOSKELETAL STIFFNESS (stiff neck) was resolving, MUSCULAR WEAKNESS (shoulder weakness to the neck and upper arm down to his knees) had resolved. At the time of the report, JOINT SWELLING (knees started swelling and became extremely weak with tendon pain), TENDON PAIN (knees started swelling and became extremely weak with tendon pain) and MYALGIA (achy shoulders) had resolved, PAIN IN EXTREMITY (arm soreness) had not resolved and HEADACHE (slight headache), ARTHRALGIA (knee pain) and PYREXIA (fever running possibly closer to 99.5F) outcome was unknown.        For mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular), the reporter did not provide any causality assessments.   Tramadol 50 mg QD every 6 hours PRN (not taken yet) Glucosamine OTC  (not taken yet) Self medication: Aspirin q 8hours for 4 days( 6 tabs a day) Switched to Tylenol extra strength q 10 hours, consumed 12 tabs for 5 days Advil 2 tabs this morning   Most recent FOLLOW-UP information incorporated above includes: On 03-May-2021: Initial additional  On 14-May-2021: On 14-MAY-2021, ADR form was attached with complete details.