Varicella Vaccination in Patients with Hematological Malignancies
Live-attenuated varicella vaccines should not be administered to patients with hematological malignancies during active treatment or within 24 months after completion of immunosuppressive therapy, but may be considered after this period for VZV-seronegative patients. 1
General Recommendations
- Live-attenuated varicella vaccines (containing the Oka strain) are contraindicated in highly immunocompromised patients with hematological malignancies during treatment due to risk of severe complications 1
- Vaccination with live-attenuated varicella vaccine should be delayed until at least 24 months after completion of immunosuppressive therapy 1
- For patients who are VZV-seronegative and at risk of exposure, passive immunization with VZV hyperimmunoglobulin (1 mL/kg) is recommended for post-exposure prophylaxis 1
Specific Patient Populations
Patients with Acute Leukemia
- Adult cancer patients seronegative for VZV show increased rates of complications (dissemination, mortality) if primarily infected 1
- Immunization against VZV may be considered >24 months after completion of therapy (CIII level recommendation) 1
- Live-attenuated vaccines should not be administered during the first 24 months following immunosuppressive treatment 1
Patients with Lymphoma, Multiple Myeloma, and Myeloproliferative Neoplasms
- Similar restrictions apply as for acute leukemia patients - live-attenuated varicella vaccines should be avoided during active treatment 1
- After 24 months post-treatment, vaccination may be considered if the patient is VZV-seronegative 1
Stem Cell Transplant Recipients
- Patients following autologous stem cell transplantation (ASCT) should not receive live-attenuated vaccines during the first 2 years following ASCT or during maintenance therapy (DIIt) 1
- After >24 months post-ASCT, vaccination with live-attenuated varicella vaccine appears to be safe 1
- For ASCT recipients beyond 24 months post-transplant, vaccination against varicella is recommended using either one dose of Zostavax or 2 doses of Varilrix (BII) 1
Emerging Evidence and Future Directions
- Inactivated VZV vaccines have shown promising results in recent trials and could change current recommendations when they become available 1
- A recent phase III trial evaluating an inactivated VZV vaccine in solid tumor patients showed efficacy with 63.6% reduction in herpes zoster, but was not efficacious in patients with hematological malignancies (16.8% efficacy) 2
- The 2025 Cochrane review indicates that herpes zoster vaccines may reduce infection risk for up to 21 months in patients with hematological malignancies, but the certainty of evidence is low 3
Special Considerations
- For VZV-seronegative patients requiring urgent treatment, vaccination should be completed at least 4 weeks before initiating immunosuppressive therapy if possible 1
- Household contacts of patients with hematological malignancies who are VZV-seronegative should be vaccinated to reduce exposure risk, but contact with the patient should be avoided if post-vaccination rash develops 1
- Regular assessment of seroprotection is recommended every 4-5 years in patients after ASCT (BIII) 1
Pitfalls and Caveats
- Severe and fatal complications have been reported with live vaccines in immunocompromised patients 4
- Vaccine virus given in the week before starting therapy for malignancy has been associated with death and has resulted in reactivation of VZV that subsequently became resistant to antiviral drugs 1
- Patients who received VZV vaccine prior to immunosuppression may retain protective immunity, reducing the need for revaccination during periods of immunosuppression 1
- Small studies in pediatric oncology patients have explored vaccination without interruption of chemotherapy, but this approach requires close monitoring and is not currently recommended for routine practice in adults 5
In conclusion, while protection against varicella is important in patients with hematological malignancies, the use of live-attenuated vaccines must be carefully timed to avoid serious complications. The emergence of inactivated VZV vaccines may provide safer alternatives in the future for this vulnerable population.