GUILLAIN BARRE SYNDROME; SUSPECTED CLINICAL VACCINATION FAILURE; BACTERIAL PNEUMONIA; COVID-19 PNEUMONIA; This spontaneous report received from a patient concerned a 58 year old female. Initial information was processed along with the additional information received on 20-DEC-2021. The patient's weight was 224 pounds, and height was 62 inches. The patient's concurrent conditions included: seasonal allergy, non-alcohol drinker, non-smoker, and diabetic, and other pre-existing medical conditions included: There was no drug abuse or illicit drug usage. The patient was not pregnant at the time of vaccination. The patient received covid-19 vaccine ad26.cov2.s (suspension for injection, route of admin not reported, batch number: 204A21A, expiry: UNKNOWN) dose was not reported, 1 total administered on 14-SEP-2021 to left deltoid for prophylactic vaccination (Dose number in series 1). Concomitant medications included vitamin B12. On 22-OCT-2021, the patient experienced nasal congestion though it was allergy. On 25-OCT-2021, the patient started coughing. On 26-OCT-2021, the patient lost taste and smell so she took quick at home test and the result was positive (Suspected Vaccination failure). On 26-OCT-2021, Laboratory data included: COVID-19 antigen test (NR: not provided) positive. On NOV-2021, Laboratory data included: Blood test (NR: not provided) Not reported, CAT scan (NR: not provided) Not reported, and Magnetic resonance imaging (NR: not provided) Not reported. On 01-NOV-2021, the patient was sent to the emergency room after a chest X-ray, at the emergency room they diagnosed her with viral pneumonia and was prescribed inhalers for it. She stayed at the emergency room for a few hours then went home. Laboratory data included: Chest X-ray (NR: not provided) diagnosed with covid-19 Pneumonia, and Spinal tap (NR: not provided) Not reported. On 08-NOV-2021, the patient was diagnosed with bacterial pneumonia after her coughing green stuff and the physician diagnosed it as bacterial pneumonia. On 11-NOV-2021, she had numbness of feet and hand and on 13-NOV-2021 she could not walk so she went to the Hospital where she was diagnosed with Guillain Barre Syndrome and was treated with immunoglobulins IV plasma doses. On 13-NOV-2021, the patient was hospitalized. The patient was discharged from the hospital on 24-NOV-2021 and got out of rehab on 02-DEC-2021. Number of days of hospitalization was 12. The patient did not know when she stopped coughing it was somewhere between 19-NOV-2021 to 22-NOV-2021. At time of this report the patient still felt numbness in hand and feet and received physical and occupational therapy 3 days a week and used a walker. Treatment medications (dates unspecified) included: Nifedipine 30mg when needed and blood pressure has started to go down, and immunoglobulins nos for guillain barre syndrome. On an unspecified date, Laboratory data included: Blood pressure (NR: not provided) elevated The action taken with covid-19 vaccine ad26.cov2.s was not applicable. The patient recovered from covid-19 pneumonia, and bacterial pneumonia on 22-NOV-2021, had not recovered from guillain barre syndrome, and the outcome suspected clinical vaccination failure was not reported. This report was serious (Hospitalization Caused / Prolonged, and Other Medically Important Condition). This report was associated with a product quality complaint:90000207520. The suspected product quality complaint has been confirmed to be the reported allegation could not be confirmed. A manufacturing related root cause could not be identified based on the RA evaluation/investigation performed.; Sender's Comments: V0: 20211238200-COVID-19 VACCINE AD26.COV2.S-COVID-19 pneumonia,  Bacterial pneumonia. These events are considered unassessable. The events have a compatible/suggestive temporal relationship, are unlabeled, and have unknown scientific plausibility. There is no information on any other factors potentially associated with the events. 20211238200-COVID-19 VACCINE AD26.COV2.S-Guillain-Barre syndrome. This event is labeled per RA and is therefore considered potentially related. 20211238200-COVID-19 VACCINE AD26.COV2.S-Suspected clinical vaccination failure. This event is considered not related. The event has a compatible/suggestive temporal relationship, is unlabeled, and has unknown scientific plausibility. There are other factors more likely to be associated with the event than the drug. Specifically: SPECIAL SITUATIONS