Varicella-Zoster virus reactivation/disseminated Herpes zoster; This is a literature report following SARS-CoV-2 immunization in two patients with leukemia. This author reported similar events for two patients. This is the first reports.  We report two cases of VZV reactivation following SARS-CoV-2 immunization in patients with an underlying hematologic malignancy. Case 1: A 17-year-old female with acute lymphoblastic leukemia (ALL) presented with a 1-month history of a vesicular rash. Two days after receipt of her first SARS-CoV-2 vaccine, she reported pain and redness over the right side of her back and subsequently developed a cluster of fluid-filled lesions. Five days after her second vaccine, she developed new lesions on her face, neck, and chest, and she was admitted to the hospital. She had primary VZV infection around 6 years of age. She was receiving methotrexate and 6-mercaptopurine and had no recent changes to her immunosuppression or other identified stressors. During admission, her lowest absolute neutrophil count (ANC) was 520 cells/mm3 and lowest absolute lymphocyte count (ALC) was 200 cells/mm3. Vesicles on her forehead and neck were unroofed and the tissue was positive for VZV by polymerase chain reaction (PCR) and negative for herpes simplex virus (HSV). A biopsy of the skin lesions on her back was performed given the unusual black eschar (Figure 1). Viral, fungal, and bacterial cultures were negative. She was treated with intravenous acyclovir and then transitioned to oral valacyclovir to complete a 2-week course of therapy and subsequently received prophylactic dosing of valacyclovir. We present two patients with underlying ALL who developed VZV reactivation following SARS-CoV-2 vaccination, indicating the need for increased vigilance in recognizing VZV reactivation in at-risk patients. Our patients demonstrated different clinical manifestations of their first episode VZV reactivation. One patient presented with disseminated Herpes zoster (HZ), while the other patient had Ramsay Hunt syndrome There are multiple reports of VZV reactivation and the development of HZ in adults with COVID-19 infection. A reduction in lymphocytes, especially CD3+ CD8+ lymphocytes, which can occur during infection with SARS-CoV-2, has been proposed as a potential mechanism triggering reactivation of herpesviruses. They published a case series of six adult patients with underlying rheumatologic conditions who developed HZ within a short timeframe following BNT162b2 vaccination. Their report suggests the need for ongoing epidemiologic studies on the safety of mRNA-based COVID-19 vaccines, especially in immunocompromised patients, to clarify if there is a link with VZV reactivation. Our first patient described the appearance of skin lesions 2 days following her first SARS-CoV-2 immunization and 5 days following her second immunization, while the second patient had a more delayed presentation at 17 days after the second immunization. The reason for the difference in time to presentation is unclear. The onset of Ram say Hunt syndrome may be more insidious than disseminated HZ; the appearance of vesicles in children with Ramsay Hunt is often delayed in comparison to adults. Additionally, both patients were immunocompromised which increases the likelihood of VZV reactivation. The incidence of HZ is five to six times higher in immunosuppressed children compared to nonimmunosuppressed children. Patient two had an increase in methotrexate dosing 3 days prior to development of symptoms, which may have increased his risk. The observed timing of reactivation after vaccination in these patients could also represent a coincidence. Our report is subject to several limitations. We would not have captured patients presenting outside of the Hospital system, nor patients who did not have a VZV PCR performed. We did not perform a comparison study between SARS-CoV-2 vaccinated and unvaccinated individuals to determine the incidence of VZV reactivation. While further studies are needed to determine if a causal relationship exists between COVID-19 vaccination and VZV reactivation, we recommend a heightened suspicion for HZ in recently vaccinated immunosuppressed patients presenting with vesicular lesions. FIGURE 1 (A) Vesicular lesions present on the right clavicle and left lower neck. (B) Crusted black eschar along the right mid-back (suture present post biopsy). (C) Right facial droop when attempting to smile; Sender's Comments: Based on the information provided the role of the vaccine BNT162B2 in triggering/contributing to the reported event varicella zoster virus infection cannot be completely excluded. Also the contributing factors of patient's medical history and concomitant medications need to be taken into consideration.  The impact of this report on the benefit/risk profile of the Pfizer product is evaluated as part of Pfizer procedures for safety evaluation, including the review and analysis of aggregate data for adverse events. Any safety concern identified as part of this review, as well as any appropriate action in response, will be promptly notified to RAs, Ethics Committees, and Investigators, as appropriate.,Linked Report(s) : US-PFIZER INC-202101203151 Same suspect/article/event and Different patient