What is the recommended herpes zoster (shingles) vaccine regimen for a liver transplant patient on immunosuppressive therapy?

Herpes Zoster Vaccination for Liver Transplant Recipients on Immunosuppressive Therapy

For liver transplant recipients on immunosuppressive therapy, the recombinant zoster vaccine (RZV) may be considered at least 4 months post-transplantation, with the exact timing depending on the immunosuppressive regimen and clinical condition. 1

Vaccine Options and Recommendations

Recombinant Zoster Vaccine (RZV)

• RZV is the preferred vaccine for immunocompromised patients including transplant recipients as it is a non-live vaccine 1
• For liver transplant recipients specifically, RZV may be considered at least 4 months post-transplantation 1
• The timing should be adjusted based on the specific immunosuppressive regimen and clinical condition of the patient 1
• RZV is administered as a two-dose series, with doses typically given 1-2 months apart 1

Live Zoster Vaccine (ZVL)

• ZVL (Zostavax) should NOT be administered to highly immunocompromised patients, including liver transplant recipients on immunosuppressive therapy 1
• The strong recommendation against ZVL is due to the risk of vaccine-strain viral infection in immunocompromised hosts 1

Evidence Supporting RZV in Transplant Recipients

Efficacy and Safety

• RZV has demonstrated favorable safety and immunogenicity profiles in solid organ transplant recipients 2, 3
• A meta-analysis showed that RZV reduced the incidence of herpes zoster by 81% across immunocompromised populations (RR: 0.19,95% CI: 0.09,0.44) 3
• In kidney transplant recipients (the most studied SOT population), RZV showed high vaccine response rates at 2 months for both humoral (80.2%) and cellular immunity (71.4%) 1

Timing Considerations

• For kidney transplant recipients, vaccination is recommended at least 4 months post-transplantation 1
• For other solid organ transplants (including liver), the optimal timing is less well-established but generally follows similar principles 1
• A small study including liver transplant recipients showed significant increases in humoral and cellular responses when RZV was administered at a median of 3.8 years post-transplantation 1

Pre-Transplant Vaccination Considerations

• If possible, zoster vaccination should be completed at least 4 weeks before beginning immunosuppressive therapy 1
• For patients aged ≥60 years, ZOS (zoster vaccine live) should be given if it can be administered ≥4 weeks before beginning highly immunosuppressive therapy 1
• For patients aged 50-59 years with varicella immunity, ZOS should be considered if it can be administered ≥4 weeks before immunosuppression 1

Special Considerations and Precautions

• The rates of injection site reactions are higher with RZV compared to placebo (approximately 80-90% vs. 9-23%), but serious adverse events appear similar between vaccinated and unvaccinated groups 1
• Immunogenicity may be lower in transplant recipients compared to immunocompetent individuals, but still provides significant protection 3
• Vaccination should ideally occur when the patient is on stable immunosuppression without recent rejection episodes 1

Practical Implementation

• Assess varicella immunity status before vaccination 1
• Consider the patient's current level of immunosuppression when determining timing 1
• For patients already on immunosuppression, RZV is preferred over ZVL due to safety concerns 1
• Monitor for injection site reactions, which are common but typically self-limited 1
• Consider prophylactic analgesics for post-vaccination discomfort 4

Conclusion

For liver transplant recipients on immunosuppressive therapy, RZV is the recommended herpes zoster vaccine and may be administered at least 4 months post-transplantation. The timing should be individualized based on the specific immunosuppressive regimen and clinical stability. ZVL should not be used in these patients due to safety concerns related to its live-attenuated nature.