What is the recommended dose for the Zostavax (Varicella Zoster vaccine)?

Zostavax Dosing Recommendation

Zostavax (zoster vaccine live) is administered as a single 0.65 mL dose subcutaneously, typically in the deltoid region of the arm. 1

Standard Dosing

• Single dose administration: Zostavax is given as a one-time subcutaneous injection of 0.65 mL 1
• No booster dose is currently licensed or recommended for this vaccine 1
• The vaccine contains approximately 14 times the potency of single-antigen varicella vaccine, with a minimum potency significantly higher than standard varicella vaccines 2, 1

Age-Specific Recommendations

• Primary indication: Adults aged ≥60 years for prevention of herpes zoster and postherpetic neuralgia 1
• Extended use: The vaccine is also approved for adults aged 50-79 years in certain contexts 2
• Vaccination should be offered at the patient's first clinical encounter with their healthcare provider 1

Special Populations

Immunocompromised Patients

• Contraindicated in highly immunocompromised patients including those with primary or acquired immunodeficiency states due to risk of serious disease from the live attenuated virus 2
• Should not be administered during the first 2 years following stem cell transplantation or while on maintenance therapy 2
• After stem cell transplantation: One dose of Zostavax can be given at >24 months post-transplant in appropriate candidates 2

HIV-Infected Patients

• Zostavax is not routinely recommended for HIV-infected adults 2
• However, administration may be considered in HIV-infected adults with CD4 ≥200 cells/μL and complete virologic suppression on antiretroviral therapy, though this remains investigational 2

Administration Technique

• Route: Subcutaneous injection 1
• Site: Deltoid region of the arm 1
• Storage: Lyophilized preparation stored frozen at -15°C or colder until reconstitution 2
• After reconstitution: Must be used within 30 minutes at room temperature 2

Pre-Vaccination Considerations

• No serologic testing required: Patients do not need to be asked about their history of varicella or have serologic testing conducted before vaccination 1
• Previous herpes zoster: The vaccine is still recommended for persons who report a previous episode of zoster 1
• Chronic medical conditions: Not a contraindication to vaccination 1

Important Limitations

• Not for acute treatment: Zostavax is not indicated to treat acute zoster, prevent PHN in those with acute zoster, or treat ongoing postherpetic neuralgia 1
• Declining efficacy over time: Real-world data shows gradual decline in vaccine efficacy over time, though continued benefit persists 3
• Vaccine effectiveness: Approximately 70% effective against herpes zoster in real-world settings, lower than the >90% efficacy of the newer recombinant zoster vaccine (Shingrix) 4

Current Clinical Context

While Zostavax remains a single-dose option, the recombinant zoster vaccine (Shingrix) is now preferred by the CDC over Zostavax due to superior efficacy and the ability to use it in immunocompromised populations 2. However, when Zostavax is used, the single 0.65 mL subcutaneous dose remains the standard administration protocol 1.