Herpes Zoster in Hematological Disorders: Pathogenesis, Risk Stratification, and Emerging Strategies for Prevention and Immunization.

BACKGROUND: Herpes zoster (HZ), resulting from reactivation of latent varicella-zoster virus (VZV), imposes a significant burden on immunocompromised patients, particularly those with hematological malignancies and recipients of hematopoietic stem cell transplants (HSCT). These populations face markedly increased risks of severe complications, including disseminated disease and postherpetic neuralgia. OBJECTIVE: This review examines the pathogenesis, epidemiology, risk factors, and evolving preventive strategies for HZ in patients with hematological disorders, with an emphasis on antiviral prophylaxis and vaccination. METHODS: Relevant data from recent clinical trials, observational studies, and international guidelines were critically reviewed to evaluate the burden of HZ and the effectiveness of prophylactic interventions in immunocompromised populations. RESULTS: Immunosuppression-whether due to the underlying disease or post-transplant immune reconstitution-compromises VZV-specific cellular immunity, thereby increasing HZ susceptibility. Incidence rates in high-risk groups, such as HSCT recipients or patients treated with proteasome inhibitors, JAK2 inhibitors, or CAR-T therapies, may exceed 30-60 per 1000 person-years. Antiviral prophylaxis remains a fundamental preventive approach. The adjuvanted recombinant zoster vaccine (aRZV) demonstrates 68%-87% efficacy even in heavily immunosuppressed individuals. Emerging vaccine platforms, including mRNA-based formulations, offer promising improvements in immunogenicity and scalability. CONCLUSION: Patients with hematological conditions are particularly vulnerable to HZ. Effective prevention requires a tailored combination of antiviral prophylaxis and aRZV immunization. The development of mRNA-based vaccines may further enhance preventive strategies for this at-risk population.