Rather moderate side effects/moderate reaction to the booster; Sleepy/slept 3 hours; 99.6 temperature; Headache, fatigue, body aches, lethargy/very lethargic; Headache, fatigue, body aches, lethargy; Headache, fatigue, body aches, lethargy; Headache, fatigue, body aches, lethargy/fatigued; This spontaneous case was reported by a pharmacist and describes the occurrence of LETHARGY (Headache, fatigue, body aches, lethargy/very lethargic), VACCINATION COMPLICATION (Rather moderate side effects/moderate reaction to the booster), SOMNOLENCE (Sleepy/slept 3 hours), HEADACHE (Headache, fatigue, body aches, lethargy) and MYALGIA (Headache, fatigue, body aches, lethargy) in a 60-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 939909) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Concurrent medical conditions included MGUS since 2018 and Hay fever.   On 17-Nov-2021, the patient received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Cutaneous) dosage was changed to 1 dosage form. On an unknown date, the patient received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On an unknown date, received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 18-Nov-2021, the patient experienced LETHARGY (Headache, fatigue, body aches, lethargy/very lethargic), HEADACHE (Headache, fatigue, body aches, lethargy), MYALGIA (Headache, fatigue, body aches, lethargy) and FATIGUE (Headache, fatigue, body aches, lethargy/fatigued). On an unknown date, the patient experienced VACCINATION COMPLICATION (Rather moderate side effects/moderate reaction to the booster), SOMNOLENCE (Sleepy/slept 3 hours) and PYREXIA (99.6 temperature). At the time of the report, LETHARGY (Headache, fatigue, body aches, lethargy/very lethargic), HEADACHE (Headache, fatigue, body aches, lethargy), MYALGIA (Headache, fatigue, body aches, lethargy) and FATIGUE (Headache, fatigue, body aches, lethargy/fatigued) had not resolved and VACCINATION COMPLICATION (Rather moderate side effects/moderate reaction to the booster), SOMNOLENCE (Sleepy/slept 3 hours) and PYREXIA (99.6 temperature) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Body temperature: high (High) 99.6 temperature.     For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter considered LETHARGY (Headache, fatigue, body aches, lethargy/very lethargic), VACCINATION COMPLICATION (Rather moderate side effects/moderate reaction to the booster), SOMNOLENCE (Sleepy/slept 3 hours), HEADACHE (Headache, fatigue, body aches, lethargy), MYALGIA (Headache, fatigue, body aches, lethargy), FATIGUE (Headache, fatigue, body aches, lethargy/fatigued) and PYREXIA (99.6 temperature) to be possibly related.    It was reported that the patient had zero reaction to the first two shots. No concomitant medication was reported. No treatment medication was reported. Leaning toward moderate for severity of events, was reported.   Most recent FOLLOW-UP information incorporated above includes: On 18-Nov-2021: Follow-up received contains new events and lab data.