Introduction: Vaccination against SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) is crucial to controlling the pandemic. Although there are not yet enough data on the coronavirus disease 2019 (COVID-19) and the risk of patients develop Multiple Sxlerosis, it is likely that older patients with higher disability and associated complications have a higher risk of complications from COVID-19 infections. Multiple sclerosis is defined as an inflammatory demyelinating disease characterized by the presence of episodes of neurological dysfunction in at least two areas of the central nervous system (brain, spinal cord and optic nerves) separated in time and space. Case report: A 37-year-old male patient, took the first dose of the pfizer vaccine in July 2021, after three months in October 2021, he started symptoms of bilateral paresthesia in the lower limbs evolving with weakness and faecal incontinence, 21 days later he sought medical service and underwent magnetic resonance imaging of the skull with the finding of eight small oval foci (> 3 mm) of hypersignal in T2 and FLAIR (Fluid-Attenuated Inversion Recovery) in the white matter of the cerebral hemispheres, including periventricular regions. without signs of acute inflammation. cerebrospinal fluid puncture showed the presence of oligoclonal bands associated with an immunoglobulin G index of 1.006 mg/dL. Vaccinated patients can present a myriad of symptoms and autoimmune disorders have been correlated to it. Conclusion: There is no cure for multiple sclerosis, the focus is the fast recovery from acute attacks reducing new relapses and slow progression of disease as well as brain atrophy and disability accumulation. To accomplish this purpose there are several disease modifying therapies for relapsing-remitting multiple sclerosis. Interferon beta medications are the most prescribed medications, with the mechanism of reducing inflammation and increasing nerve growth. Patients taking interferons need blood tests to monitor liver enzymes and experience side effects.

Acute necrotizing esophagitis (black esophagus) is a rare clinical entity that is characterized by partial or total loss of the epithelium, ulceration up to the circumferential slough of all layers of the mucosa and submucosal, frequent involvement of deep muscle layers, and frequent perforations. Its blackish appearance in endoscopic examinations has given it the name of black esophagus. We describe a rare case of black esophagus caused by hepatic cirrhosis associated with gastric ulcer.