Muscle weakness/muscle fatigue; Just fallen while trying to beach the paddle board; Shaky legs; His walking as slowed; Fever; Chills; This spontaneous case was reported by a consumer and describes the occurrence of MUSCULAR WEAKNESS (Muscle weakness/muscle fatigue), FALL (Just fallen while trying to beach the paddle board), TREMOR (Shaky legs), GAIT DISTURBANCE (His walking as slowed) and PYREXIA (Fever) in a 52-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 prophylaxis. The occurrence of additional non-serious events is detailed below.    Co-suspect product included non-company product ALGLUCOSIDASE ALFA for Pompe's disease.    No Medical History information was reported.   On 12-Dec-2006, the patient started ALGLUCOSIDASE ALFA (Intravenous) 1500 milligram every two weeks. On an unknown date, the patient received dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On an unknown date, the patient experienced MUSCULAR WEAKNESS (Muscle weakness/muscle fatigue), FALL (Just fallen while trying to beach the paddle board), TREMOR (Shaky legs), GAIT DISTURBANCE (His walking as slowed), PYREXIA (Fever) and CHILLS (Chills). At the time of the report, MUSCULAR WEAKNESS (Muscle weakness/muscle fatigue), FALL (Just fallen while trying to beach the paddle board) and TREMOR (Shaky legs) outcome was unknown and GAIT DISTURBANCE (His walking as slowed), PYREXIA (Fever) and CHILLS (Chills) had resolved.     The action taken with mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown) was unknown.  Concomitant product use was not provided by the reporter.  It was unknown 0.2-micron inline filter used or not.   On an unknown date the patient developed a muscle weakness, muscle fatigue, just fallen while trying to beach the paddle board, shaky legs, his walking as slowed, fever and chills following the first dose intake of ALGLUCOSIDASE ALFA and ELASOMERAN.  It was reported patient reports being excited about the new drug as he can see slow regression over time. Patient had discussed regression previously with healthcare professional. He states that Enzyme replacement therapy had probably flattened the progression of his muscle weakness. He also talks about limitations and modifications he had to paddle board. He states he cannot push up and stand from his knees and had to board from the shore in a standing position, backing up and sliding his feet gently as the stability of the board decreases as it moves from being grounded to floating. He also talks about having just fallen while trying to beach the paddle board. Patient talks about the muscle fatigue and shaky legs after paddle boarding for a while and the need for him to be extremely careful while stepping off the board onto the shore. The patient had his Moderna Covid-19 Vaccine booster and experienced fever and chills. He also reported that his walking has slowed.  No action taken with lumizyme.  It was not reported if the patient received a corrective treatment for the events.  This case was identified as part of a retrospective clean-up activity where certain emails received in the Moderna mailbox were missed to be booked-in.   This case was linked to MOD-2021-624508 (Patient Link).