DEATH; INTENSIVE CARE; MECHANICAL VENTILATION; GUILLAIN-BARRE SYNDROME; This spontaneous report was received from a health care professional via a Regulatory Authority the VAERS (Vaccine Adverse Event Reporting System) via literature. This report concerned a 57-year-old male of unknown race and ethnicity. The objective of this study was to assess reports of Guillain-Barre Syndrome (GBS) received in the Vaccine Adverse Event Reporting System (VAERS) following vaccination with covid-19 vaccine ad26.cov2.s. The patient's height, and weight were not reported. No past medical history or concurrent conditions were reported. The patient received covid-19 vaccine ad26.cov2. s (suspension for injection, intramuscular, batch number: 1808609 and expiry: UNKNOWN) dose and vaccination site not reported, 1 total administered on 01-APR-2021 for prophylactic vaccination. Concomitant medications were not reported. On an unspecified date in APR-2021, within a week after vaccination, the patient experienced pain and weakness, the patient experienced Guillain-Barre syndrome and was hospitalized (date unspecified), including 6 days on a ventilator. The patient was in intensive care on mechanical ventilation. Reporter's contact with the patient and doctor was unsuccessful but attempts were continuing. The patient was treated with a course of intravenous immunoglobulin. On 26-APR-2021, 25 days after vaccination the patient died from unknown cause of death. It was unknown if an autopsy was performed. Duration of hospitalization was not reported. The action taken with covid-19 vaccine ad26.cov2.s was not applicable. The author suggests a potential small but statistically significant safety concern for Guillain-Barre Syndrome following receipt of the covid-19 vaccine ad26.cov2.s. However, the findings are subject to the limitations of passive reporting systems and presumptive case definition, and they must be considered preliminary pending analysis of medical records to establish a definitive diagnosis. The patient died due to unknown cause of death on 26-APR-2021, and the outcome of guillain-barre syndrome, intensive care and mechanical ventilation was not reported.  This report was serious (Death, Hospitalization Caused / Prolonged, and Life Threatening).  This case, from the same reporter is linked to 20211021308. This case, from same literature article is linked to 20211021340, 20211021338, 20211021361 and 20211021284.  Additional information was received on 11-OCT-2021. It was determined that Manufacture Case number (20211021308) was a duplicate of this case.  All relevant information (new event death and date of death added) this case will be submitted under a Manufacturer Case Number (20210514945).; Sender's Comments: V1- This follow up updates- .  All relevant information (new event death and date of death added) regarding duplicate Manufacture Case number (20211021308).  20210514945-COVID-19 VACCINE AD26.COV2.S-Guillain-Barre syndrome, This event(s) is considered related. The event(s) has a compatible/suggestive temporal relationship, is unlabeled, and is scientifically plausible. There is no information on any other factors potentially associated with the event(s).  20210514945-COVID-19 VACCINE AD26.COV2.S- Intensive care, mechanical ventilation. This event(s) is considered unassessable. The event(s) has a compatible/suggestive temporal relationship, is unlabeled, and has unknown scientific plausibility. There is no information on any other factors potentially associated with the event(s).  20210514945-COVID-19 VACCINE AD26.COV2.S Death. Follow-up received regarding Clinical Details. This event(s) is considered unassessable. The event(s) has a compatible/suggestive temporal relationship, is unlabeled, and has unknown scientific plausibility. There is no information on any other factors potentially associated with the event(s).; Reported Cause(s) of Death: UNKNOWN CAUSE OF DEATH