Entire right arm paralyzed for 16 hours, 4 hours after 2nd booster; Lied on the couch, and Could not use his right arm; 2nd half dose Booster dose on 09-Apr-2022 (only 3 months after the first half dose); Pain in the right shoulder 4 hours after 2nd booster; This spontaneous case was reported by a consumer and describes the occurrence of MONOPLEGIA (Entire right arm paralyzed for 16 hours, 4 hours after 2nd booster) in a 57-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 001B21A, 047B21A and 059H21A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.  The patient was clear and healthy. Previously administered products included for Product used for unknown indication: VARICELLA ZOSTER VACCINE (The side effect went away in 36 hours) on 06-Apr-2022 and VARICELLA ZOSTER VACCINE (The side effect went away in 36 hours) on 06-Apr-2022. Past adverse reactions to the above products included Fatigue with VARICELLA ZOSTER VACCINE; and Pain in arm with VARICELLA ZOSTER VACCINE.   On 18-Mar-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 15-Apr-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 29-Dec-2021, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 09-Apr-2022, received fourth dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 09-Apr-2022, the patient experienced MONOPLEGIA (Entire right arm paralyzed for 16 hours, 4 hours after 2nd booster) (seriousness criterion medically significant), VACCINATION SITE MOVEMENT IMPAIRMENT (Lied on the couch, and Could not use his right arm), INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION (2nd half dose Booster dose on 09-Apr-2022 (only 3 months after the first half dose)) and VACCINATION SITE PAIN (Pain in the right shoulder 4 hours after 2nd booster). On 11-Apr-2022, MONOPLEGIA (Entire right arm paralyzed for 16 hours, 4 hours after 2nd booster) had resolved. At the time of the report, VACCINATION SITE MOVEMENT IMPAIRMENT (Lied on the couch, and Could not use his right arm) was resolving, INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION (2nd half dose Booster dose on 09-Apr-2022 (only 3 months after the first half dose)) outcome was unknown and VACCINATION SITE PAIN (Pain in the right shoulder 4 hours after 2nd booster) had not resolved.  Patient stated 4 hours after the 2nd half dose booster (4th shot), he developed pain in the right shoulder (rating 8-9 on a scale of 1-10), lied on the couch, and could not use his right arm and entire right arm was paralyzed for 16 hours. He did not took medications and did not call a doctor. On 11-Apr-2022, he felt better and could lift his arm but he still felt the pain. No concomitant medications were provided by reporter.  Company comment: This spontaneous case concerns a 57 year old male patient, with no reported medical history, who experienced the unexpected serious (important medical event) event of Monoplegia, about 4 hours after receiving the fourth dose (2nd booster dose) of mRNA-1273 vaccine. Patient described that he developed pain in the right shoulder (rating 8-9 on a scale of 1-10), lied on the couch and could not use his right arm. Entire right arm was paralyzed for 16 hours. No further information on management of the event was available in the report. The outcome of the event was 'recovering'. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.   This case was linked to MOD-2022-537571, MOD-2022-537572, MOD-2022-537568 (Patient Link).; Sender's Comments: This spontaneous case concerns a 57 year old male patient, with no reported medical history, who experienced the unexpected serious (important medical event) event of Monoplegia, about 4 hours after receiving the fourth dose (2nd booster dose) of mRNA-1273 vaccine. Patient described that he developed pain in the right shoulder (rating 8-9 on a scale of 1-10), lied on the couch and could not use his right arm. Entire right arm was paralyzed for 16 hours. No further information on management of the event was available in the report. The outcome of the event was 'recovering'. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.