Herpes zoster; This is a literature report, Program ID for the following literature source(s).  A 44-year-old female patient received bnt162b2 (COMIRNATY), as dose number, unknown, single (Batch/Lot number: unknown) for covid-19 immunisation; methylprednisolone (METHYLPREDNISOLONE), since 2019, intravenous for relapsing-remitting multiple sclerosis; dimethyl fumarate (TECFIDERA), first regimen since 2015 (Batch/Lot number: unknown) at 120 mg 2x/day, second regimen since 2017 (Batch/Lot number: unknown) at 240 mg 2x/day and third regimen since Jan2021 (Batch/Lot number: unknown) for relapsing-remitting multiple sclerosis. The patient's relevant medical history included: "RRMS" (unspecified if ongoing), notes: diagnosed with RRMS in 2012, at the age of 35 years. Concomitant medication(s) included: INTERFERON BETA-1A taken for relapsing-remitting multiple sclerosis. The following information was reported: HERPES ZOSTER (hospitalization), outcome "recovering". The patient underwent the following laboratory tests and procedures: CD8 lymphocytes: (unspecified date) lower proportions; Magnetic resonance imaging head: (2017) gadolinium-enhancing lesion; Natural killer cell count: (2017) elevation. The action taken for methylprednisolone and dimethyl fumarate was unknown. Therapeutic measures were taken as a result of herpes zoster.  Additional information: A 44-year-old woman developed Herpes zoster (HZ) during treatment with dimethyl fumarate and methylprednisolone for relapsing remitting multiple sclerosis (RRMS) and following vaccination with tozinameran against COVID-19 [not all routes stated; dosages and duration of treatments to reaction onset not stated]. The woman was diagnosed with RRMS in 2012, at the age of 35 years. She was treated with interferonbeta- 1a, which was discontinued later. In 2015, she started receiving dimethyl fumarate [Tecfidera] 120mg twice daily. In 2017, she presented with onset of double vision [aetiology not stated]. Brain MRI showed a gadolinium-enhancing lesion, however, not anatomically correlated with the symptoms. She was treated with methylprednisolone with resolution in symptoms. Thereafter, her dimethyl fumarate dosage was increased to 240mg twice daily. In 2019, she presented with right hand numbness with diminished dexterity and left lower extremity numbness. She started receiving IV methylprednisolone therapy. Later, she developed COVID-19 infection [aetiology not stated]. Thus, she discontinued dimethyl fumarate therapy for 1 month in July 2020 and continued thereafter. In January 2021, she started receiving the generic form of dimethyl fumarate. In July 2021 and August 2021, she received her tozinameran [Pfizer-BioNTech COVID-19 mRNA vaccine; BNT162b2] vaccination. In October 2021, she presented with subacute onset of right temple pain which progressed into jaw pain, associated with a few blisters located in the right lips corner. HZ was considered, which was secondary to dimethyl fumarate, methylprednisolone and tozinameran therapies. The woman started treatment with aciclovir [acyclovir] and prednisone. She presented to the emergency room due to HZ. Eventually, she was hospitalised and treated with aciclovir. After admission, generic form of dimethyl fumarate was discontinued. Lymphocytes subpopulations count after discontinuation showed lower proportions of CD8+ T cells and higher percentages of natural killer cells. She was discharged on aciclovir, with resolution in HZ. She was scheduled to receive zoster vaccine in 1 year. Few days later, she developed new low left lower extremity numbness and weakness along with urinary retention. MS exacerbation was diagnosed. Eventually, her dimethyl fumarate therapy was restarted along with valaciclovir [valacyclovir]. Few weeks later, elevation of the NK cells was observed, which was suspected to be HZ reactivation [aetiology not stated]. She was treated with methylprednisolone along with physical therapy with improvement in her condition. MS exacerbation was secondary to HZ.; Sender's Comments: Based on the limited information provided in this case, a contributory role of the suspect product BNT162b2 (COMIRNATY) to the reported event cannot be excluded. Event is considered Related conservatively. There is very limited information provided in this report. Case will be reassessed upon receipt of additional information.