Varicella-zoster virus reactivation after SARS-CoV-2 BNT162b2 mRNA vaccination: Report of 5 cases

VZV: varicella-zoster virus INTRODUCTION A few months ago, we reported that to consider vesicular exanthems associated with COVID-19, varicella-zoster virus (VZV) and herpes simplex virus must be ruled out. The natural history of herpes zoster is influenced by the immune status of the host. Reactivation is influenced by age-related immunosenescence, disease-related immunocompromised state, or iatrogenic immunosuppression, with age being the major risk factor for most cases of herpes zoster. Among VZVreactivation triggers, vaccines are not common, and excluding herpes zoster appearing after VZV vaccination, we have found only 1 case of a child who experienced herpes zoster after diphtheria/tetanus/acellular pertussis, inactivated polio, Haemophilus influenzae type b, and meningococcal C vaccine. Nonetheless, the patient had also previously received an allogeneic hematopoietic transplant, which is a possible confounding factor. Recently, a single case of herpes zoster after an mRNA COVID-19 vaccine has been reported.