What is the recommended dosing schedule for herpes zoster vaccination (Shingrix [recombinant adjuvanted zoster vaccine] and Zostavax [live attenuated zoster vaccine]) in adults, including age and immunocompromised considerations?

Shingles Vaccine Dosing Schedule

For adults aged 50 years and older, administer Shingrix (recombinant zoster vaccine) as a 2-dose series with the second dose given 2-6 months after the first dose, with a minimum interval of 4 weeks between doses. 1, 2

Standard Dosing for Immunocompetent Adults

• Shingrix is the preferred vaccine for all adults aged ≥50 years, administered intramuscularly as two doses separated by 2-6 months 2, 3
• The minimum acceptable interval between doses is 4 weeks, though this is not optimal 1, 2
• If the second dose is given beyond 6 months, effectiveness remains intact—do not restart the series 2
• Shingrix demonstrates 97.2% efficacy in preventing herpes zoster in adults aged ≥50 years, with protection maintained above 83.3% for at least 8 years 2

Accelerated Schedule for Immunocompromised Adults

• For immunocompromised adults aged ≥18 years, administer the second dose 1-2 months after the first dose to provide earlier protection in this high-risk population 1, 2
• The 4-week minimum interval still applies even in immunocompromised patients 1, 2
• Shingrix is safe and appropriate for immunocompromised patients, unlike the live-attenuated Zostavax which is absolutely contraindicated 1, 2

Zostavax (Live-Attenuated Vaccine) - Historical Context

The older guidelines from 2007-2009 recommended Zostavax as a single dose for adults aged ≥60 years 4. However, this vaccine is no longer preferred due to:

• Significantly inferior efficacy (51% initially, declining to only 14.1% by year 10) compared to Shingrix's sustained 92% effectiveness 2
• Contraindication in immunocompromised patients due to risk of disseminated VZV infection 1, 2
• Poor long-term protection requiring revaccination with Shingrix 2

Transitioning from Zostavax to Shingrix

• Adults who previously received Zostavax should receive the full 2-dose Shingrix series at least 2 months after the Zostavax dose 1, 2
• Do not count the prior Zostavax dose toward the Shingrix series—both Shingrix doses are required 2
• This recommendation applies regardless of how long ago Zostavax was administered 2

Special Timing Considerations

After a herpes zoster episode:

• Wait until acute symptoms have resolved, typically at least 2 months after the episode, before administering Shingrix 1, 2
• Prior herpes zoster does not eliminate the need for vaccination, as the 10-year recurrence risk is 10.3% 1, 2

For patients starting immunosuppressive therapy (e.g., JAK inhibitors):

• Ideally complete the full 2-dose series before initiating immunosuppressive therapy to maximize immune response 2
• If urgent therapy initiation is required, give at least the first dose before starting treatment, then complete the second dose 1-2 months later 2

For hematopoietic stem cell transplant recipients:

• Allogeneic HSCT: administer at least 6-12 months post-transplantation 1
• Autologous HSCT: vaccination can begin 50-70 days post-transplantation 1

Critical Pitfalls to Avoid

• Never use Zostavax in immunocompromised patients—only Shingrix is appropriate for this population 1, 2
• Do not delay the second Shingrix dose unnecessarily; if given late, simply administer it without restarting the series 2
• Do not confuse varicella (chickenpox) vaccine with herpes zoster vaccine—these are different vaccines for different indications 2
• Do not administer Shingrix to adults under age 50 unless they are immunocompromised (aged ≥18 years) 2
• Do not give prophylactic acetaminophen before Shingrix, as there is no evidence supporting this practice and it may theoretically reduce immune response 5

No Booster Doses Required

• No additional booster doses beyond the initial 2-dose series are currently recommended by any guidelines 2
• Protection remains robust for at least 8 years without additional doses 2