AMYOTROPHIC LATERAL SCLEROSIS; PAINFUL AND TENDER INFLAMMATION AT THE INJECTION SITE ON LEFT SIDE; This spontaneous report was received from physician via literature: This report concerned a 47 year old male of an unspecified race and ethnicity. The objective of this study was to present one of the first cases of a previously healthy male who started experiencing symptoms of ALS after receiving the J and J viral vector covid-19 vaccine. The patient's height, and weight were not reported. The patient's concurrent conditions included: depression, anxiety, hypertension, and obesity. Patient was a healthy right-handed mailman with no functional disability who walked about 10 miles every day before vaccination. Patient had family history of diabetes, hypertension, and coronary artery disease in mother, and amyotrophic lateral sclerosis (ALS) in grandmother. The patient received covid-19 vaccine ad26.cov2.s (suspension for injection, route of admin, and batch number were not reported, expiry: unknown) dose, start therapy date were not reported, 1 total was administered on left side for covid-19 prophylaxis. The batch number was not reported. Per procedure, no follow-up will be requested for this case. Age at time of vaccination 5 decade old. No concomitant medications were reported.  On an unspecified date, the patient started to experience symptoms one day after receiving the janssen viral vector vaccine. After receiving JANSSEN COVID-19 VACCINE, the patient noticed symptoms on his left side. The patient first developed painful and tender inflammation at the injection site. Within one week, his symptoms developed into left-sided arm weakness and a weak hand grip. Over the next several months, this progressed to left upper and lower extremity weakness, declining speech, dysphagia, and recurrent falls for nine months and presented to the clinic. Magnetic resonance imaging of his entire spine and brain was negative except for age-related degenerative defects and left-sided foraminal narrowing at c4-c5 and c5-c6. On examination, he was found to have left arm fasciculations, left arm atrophy, spasticity, and hyperreflexia. Babinski's sign and Hoffman's sign were present bilaterally. The patient had spastic dysarthria, a sustained clonus at both ankles, and a pseudobulbar affect with intact sensory symptoms, coordination, and gait. Labs were unremarkable. The patient was eventually referred to a neurologist and was diagnosed with amyotrophic lateral sclerosis (ALS) with a pseudobulbar affect after electromyography. Patient was prescribed Riluzole and followed up as an out-patient. The action taken with covid-19 vaccine ad26.cov2.s was not applicable. The outcome of the amyotrophic lateral sclerosis and painful and tender inflammation at the injection site on left side was not reported. The authors emphasized the need for ongoing surveillance and monitoring of adverse events following vaccination, especially in populations with unique medical histories or conditions. Secondly, it underscored the importance of conducting further research to understand the potential link between the vaccine and the development of ALS, particularly in light of the patient's family history. Although the precise pathophysiology remained unclear, it may be related to the enhanced immune response observed after administering the vaccine. Finally, the case highlighted the importance of ongoing education and training for healthcare providers to stay informed about the latest research, guidelines, and best practices related to vaccine administration and safety. This report was serious (Other Medically Important Condition).; Sender's Comments: V0:20230408070- Amyotrophic lateral sclerosis. 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. Specifically: MEDICAL HISTORY. Therefore, this event is considered inconsistent with vaccine administration.