She has difficulty walking and getting in and out of a chair since receiving the second booster dose; she couldn't get in and out of a chair" without assisstance; 101 degrees Fahrenheit temp; tips of her fingers started tingling; both of her ankles became swollen; knees became painful and knees were so bad/both shoulders hurting really bad/joints hurting really bad/experiencing arthralgia from the second booster; both of her ankles retaining water; sore right arm; didn't feel good,"felt crummy"; This spontaneous case was reported by a patient and describes the occurrence of ARTHRALGIA (knees became painful and knees were so bad/both shoulders hurting really bad/joints hurting really bad/experiencing arthralgia from the second booster), GAIT DISTURBANCE (She has difficulty walking and getting in and out of a chair since receiving the second booster dose), JOINT SWELLING (both of her ankles became swollen), FEELING ABNORMAL (didn't feel good,"felt crummy") and FLUID RETENTION (both of her ankles retaining water) in a 77-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 005M21A, 012L20A, 012M20A and 045R21A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Concurrent medical conditions included Diabetes (Recent change in status such as improvement or worsening: Well controlled) since 2019, Breast cancer (Recent change in status such as improvement or worsening: Improvement/remission) since 05-Dec-2020, Mitral valve disease NOS (Heart Condition tachycardia/mitral valve problem: 60 years ago started and no change was reported.), Drug allergy (Allergic to versed), Drug allergy (Allergic to Demerol), Allergy to antibiotic (Allergic to Biaxin), Drug allergy (Allergic to MS Contin), Iodine allergy (Allergic to Iodine (internal)), Allergy to antibiotic (Allergic to Cipro), Dairy intolerance (Allergic to All Dairy), Egg allergy (Allergic to Eggs), Allergy to nuts (Allergic to Nuts), Food allergy (Allergic to Seeds) and Tachycardia (Heart Condition tachycardia/mitral valve problem: 60 years ago started and no change was reported.). Concomitant products included SOTALOL HYDROCHLORIDE (BETAPACE), PANTOPRAZOLE, CETIRIZINE HYDROCHLORIDE (ZYRTEC [CETIRIZINE HYDROCHLORIDE]), EMPAGLIFLOZIN (JARDIANCE), LOSARTAN and ANASTROZOLE for an unknown indication.   On 09-Jan-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) .5 milliliter. On 08-Feb-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to .5 milliliter. On 27-Aug-2021, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to .25 milliliter. On 29-Apr-2022, received fourth dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to .25 milliliter. On 29-Apr-2022,  after starting mRNA-1273 (Moderna COVID-19 Vaccine), the patient experienced VACCINATION SITE PAIN (sore right arm). In May 2022, the patient experienced ARTHRALGIA (knees became painful and knees were so bad/both shoulders hurting really bad/joints hurting really bad/experiencing arthralgia from the second booster), JOINT SWELLING (both of her ankles became swollen), FLUID RETENTION (both of her ankles retaining water) and PARAESTHESIA (tips of her fingers started tingling). On an unknown date, the patient experienced GAIT DISTURBANCE (She has difficulty walking and getting in and out of a chair since receiving the second booster dose), FEELING ABNORMAL (didn't feel good,"felt crummy"), LOSS OF PERSONAL INDEPENDENCE IN DAILY ACTIVITIES (she couldn't get in and out of a chair" without assisstance) and PYREXIA (101 degrees Fahrenheit temp). At the time of the report, ARTHRALGIA (knees became painful and knees were so bad/both shoulders hurting really bad/joints hurting really bad/experiencing arthralgia from the second booster), GAIT DISTURBANCE (She has difficulty walking and getting in and out of a chair since receiving the second booster dose), JOINT SWELLING (both of her ankles became swollen), FLUID RETENTION (both of her ankles retaining water), LOSS OF PERSONAL INDEPENDENCE IN DAILY ACTIVITIES (she couldn't get in and out of a chair" without assisstance), PARAESTHESIA (tips of her fingers started tingling) and PYREXIA (101 degrees Fahrenheit temp) had not resolved, FEELING ABNORMAL (didn't feel good,"felt crummy") had resolved and VACCINATION SITE PAIN (sore right arm) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Body temperature: 101 (High) 101 degrees Fahrenheit temperature..         Treatment included water pills for treatment of swollen ankle.  The patient received her second Moderna booster dose on 29-Apr-2022. The intramuscular injection was given into her right deltoid. After the dose, she reported experiencing a sore right arm. She stated three or four days after receiving the second Moderna booster dose, her knees became painful and her knees were "so bad she couldn't get in and out of a chair" without assistance. She also stated both shoulders and her joints also began hurting "really bad," and the tips of her fingers started tingling. Both of her ankles also became swollen and "were retaining water". After receiving the second Moderna booster dose, she "didn't feel good" and "felt crummy" for one week. She also reported experiencing a 101 degrees Fahrenheit temperature. She thinks she was experiencing arthralgia from the second booster dose. She stated she has had difficulty walking and getting in and out of a chair since receiving the second booster dose. She stated she hasn't experienced anything like this before in the past.