Varicella‐Zoster virus reactivation following SARS‐CoV‐2 immunization in two patients with leukemia

Abstract

To the Editor In response to the coronavirus disease 2019 (COVID-19) pandemic, several vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been approved for use.1–3 BNT162b2 manufactured by Pfizer Inc. is the vaccine currently available for children and young adults in our hospitals and clinics. Monitoring for potential adverse vaccine events is particularly needed in high-risk patients excluded from initial vaccine clinical trials.1 Varicella-zoster virus (VZV) establishes latency in sensory ganglia following primary infection with wild-type VZV or vaccine strain.4,5 It is unclear if nonVZV immunization also can be associated with VZV reactivation.6 We report two cases ofVZV reactivation following SARS-CoV-2 immunization in patientswith an underlying hematologicmalignancy inHouston, Texas. 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 6mercaptopurine, 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