What is the recommended Shingrix (recombinant zoster vaccine) dosing schedule, interval, route, dose, and contraindications for an elderly adult (≥65 years), and how should prior receipt of Zostavax (live‑attenuated zoster vaccine) be managed?

Shingrix Vaccination Schedule for Elderly Adults

Primary Recommendation

All adults aged ≥65 years should receive the two-dose Shingrix series with the second dose administered 2–6 months after the first dose, given intramuscularly, regardless of prior Zostavax vaccination or previous herpes zoster history. 1

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Standard Dosing Schedule

• Route: Intramuscular (IM) injection 2
• Dose: Two-dose series 1
• Interval: Second dose given 2–6 months after the first dose 1
• Minimum interval: 4 weeks between doses; if administered earlier than 4 weeks, the dose must be repeated 1
• Maximum interval: No maximum interval exists—if the second dose is delayed beyond 6 months, simply administer it as soon as possible without restarting the series 1

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Efficacy and Duration of Protection

• Shingrix demonstrates 97.2% efficacy against herpes zoster in adults aged ≥50 years, with consistent protection across all age groups including those ≥65 years 1
• Protection remains ≥83.3% for at least 8 years and declines to approximately 73% at 10 years post-vaccination 1
• Real-world effectiveness in Medicare beneficiaries aged >65 years shows 70.1% effectiveness for the two-dose series and 56.9% for a single dose 3
• Efficacy against postherpetic neuralgia is 88.8% in adults ≥70 years 4 and 76.0% in real-world Medicare populations 3

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Management of Prior Zostavax Recipients

Adults who previously received Zostavax should receive the full two-dose Shingrix series, with the first dose administered at least 2 months after the last Zostavax dose. 1

Rationale for Revaccination

• Zostavax efficacy wanes dramatically over time, declining to only 14.1% by year 10 1
• Shingrix offers significantly superior efficacy (>90%) compared to Zostavax (46–70% initially) 1, 5
• Studies demonstrate no interference in immune response when Shingrix is given after prior Zostavax vaccination 2
• In adults who received Zostavax >5 years prior, Shingrix immune responses were non-inferior to those never vaccinated with Zostavax 2

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Contraindications and Precautions

Absolute Contraindications

• Severe allergic reaction (e.g., anaphylaxis) to any component of Shingrix or after a previous dose of Shingrix 1

Important Safety Notes

• Shingrix is NOT a live vaccine—it is a recombinant subunit vaccine and is therefore safe for immunocompromised individuals, unlike Zostavax which is contraindicated in this population 1, 6
• Defer vaccination during acute moderate-to-severe illness until symptoms resolve, though minor illness (e.g., mild upper respiratory infection) is not a contraindication 1

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Special Populations

Immunocompromised Elderly Adults (≥65 years)

For immunocompromised adults, use a shortened schedule with the second dose given 1–2 months after the first dose to achieve earlier protection. 1

Eligible immunocompromised groups include:

• Adults on chronic high-dose corticosteroids (≥20 mg/day prednisone equivalent) 4
• Patients with hematologic malignancies receiving or having completed cancer therapy 1
• Solid organ transplant recipients 1
• Autologous hematopoietic stem cell transplant (HSCT) recipients—administer first dose 50–70 days post-transplant 1
• Adults with HIV infection 4
• Patients on immunosuppressive therapy for autoimmune diseases 1

Patients with Prior Herpes Zoster

• Vaccination is recommended regardless of prior shingles history because natural infection does not provide reliable protection against recurrence 1
• The 10-year cumulative recurrence risk is 10.3% 1
• Administer Shingrix once acute symptoms have resolved, typically waiting ≥2 months after the episode 1

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Safety Profile and Common Adverse Events

• Injection-site reactions (pain, redness, swelling) occur in 9.5% of recipients (grade 3) versus 0.4% with placebo 1
• Systemic symptoms (fever, fatigue, myalgia, headache) occur in 11.4% of recipients versus 2.4% with placebo 1
• Most adverse reactions are transient, mild-to-moderate, and resolve within approximately 4 days 1, 7
• Serious adverse events and mortality rates are no different between vaccine and placebo groups 1
• In prelicensure trials, 85% of recipients reported local or systemic reactions, with approximately 17% experiencing grade 3 reactions, but serious adverse event rates were similar to placebo 7

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Concomitant Vaccination

• Shingrix can be administered simultaneously or sequentially with inactivated influenza vaccines without any required waiting period 1, 2
• Shingrix can be coadministered with PNEUMOVAX 23 or PREVNAR 13 without evidence of decreased immunogenicity or safety concerns 2
• No interference in immune response occurs when Shingrix is given with other inactivated vaccines 2

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Important Clinical Caveats

• Never restart the series if the second dose is delayed—simply administer the second dose as soon as possible regardless of elapsed time 1
• Do not give a third dose under any circumstance; the series consists of only two doses 1
• Do not order serologic testing to assess VZV immunity before vaccination in adults ≥50 years—guidelines explicitly recommend against this practice 1
• Do not use Zostavax in immunocompromised patients; only Shingrix is appropriate for this population 1, 6
• Do not delay vaccination to obtain antibody titers or wait for "optimal timing"—administer as soon as the patient is eligible 1

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Real-World Uptake and Series Completion

• In the first two years post-licensure (October 2017–September 2019), 7,097,441 first doses and 4,277,636 second doses were administered in the United States 8
• Among patients receiving a first dose, 70% completed the two-dose series within 6 months and 80% within 12 months 8
• Second doses administered ≥180 days after the first dose maintain full effectiveness with no impairment 3