For an adult patient uncertain about prior herpes zoster vaccination, what is the recommended vaccination strategy?

Shingles Vaccination for Patients with Uncertain Vaccination Status

Administer the full 2-dose Shingrix series immediately, regardless of any prior vaccination history, with the second dose given 2-6 months after the first dose. 1

Primary Recommendation

The recombinant zoster vaccine (Shingrix/RZV) is indicated for all adults aged ≥50 years, and the FDA label explicitly states this applies regardless of prior herpes zoster vaccination history. 2 When a patient is uncertain about their vaccination status, the safest and most effective approach is to proceed with the complete 2-dose series without delay. 1

There is no harm in administering Shingrix to someone who may have previously received it or the older Zostavax vaccine. 1 In fact, adults who previously received Zostavax should receive the full 2-dose Shingrix series because Zostavax provides inadequate long-term protection, with efficacy declining to only 14.1% by year 10. 1

Dosing Schedule

• Administer the first dose immediately. 1
• Give the second dose 2-6 months after the first dose. 1
• The minimum acceptable interval between doses is 4 weeks, though this is not the preferred timing. 1
• If the second dose is given beyond 6 months, effectiveness is not impaired—real-world data shows doses given at ≥180 days maintain full effectiveness. 3

Why Not Check Vaccination Records or Antibody Titers?

Do not delay vaccination to search for records or obtain antibody testing. 1 This approach contradicts guideline recommendations and leaves the patient unnecessarily exposed to herpes zoster. 1

• CDC, Canadian, and German guidelines issue a strong recommendation that varicella-history review or laboratory testing should not be performed before administering herpes zoster vaccination to adults ≥50 years. 1
• Commercial VZV IgG ELISA assays were designed to detect high antibody titers from natural varicella infection and have suboptimal sensitivity for the lower titers generated by vaccines—they are not optimized to identify vaccine-induced antibodies. 1
• Herpes zoster arises from reactivation of latent VZV due to declining cell-mediated immunity, not from low antibody titers; therefore, antibody levels do not reliably predict zoster risk. 1
• Routine serologic screening would identify very few truly seronegative individuals, adds unnecessary cost, and delays protective vaccination. 1

Safety of Revaccination

No safety concerns have been identified when giving Shingrix to individuals who may have already received it. 1 The vaccine has an acceptable safety profile, with the most common adverse reactions being injection-site pain (22.5%), fever (23.6%), and injection-site erythema (20.1%). 4 Most solicited adverse reactions are transient and mild to moderate in severity, typically resolving within 4 days. 1, 5

Serious adverse events occurred at similar rates in vaccine and placebo groups in clinical trials (approximately 3% of reports). 4

Clinical Efficacy

Shingrix demonstrates 97.2% efficacy in preventing herpes zoster in adults aged ≥50 years, with protection persisting for at least 8 years with minimal waning (maintaining efficacy above 83.3%). 1, 5 Real-world effectiveness studies show 70.1% effectiveness for the 2-dose series and 56.9% for a single dose, emphasizing the importance of completing both doses. 3

Common Pitfalls to Avoid

• Never use the live-attenuated Zostavax in immunocompromised patients—only Shingrix is appropriate for this population. 1, 6
• Do not confuse varicella (chickenpox) vaccination with herpes zoster vaccination—if the patient were truly VZV-seronegative (never had chickenpox), they would need varicella vaccine (2 doses, 4 weeks apart), not shingles vaccine. 1
• Do not delay the second dose beyond 6 months out of concern for reduced efficacy—delayed second doses maintain full effectiveness. 3
• Do not withhold vaccination from patients on low-dose glucocorticoids (<10 mg/day prednisone equivalent)—concomitant low-dose glucocorticoids do not adversely impact vaccine response. 1

Special Populations

For immunocompromised adults aged ≥18 years who are or will be at increased risk due to immunodeficiency or immunosuppression, Shingrix is indicated and should be given as a 2-dose series with a shortened interval of 1-2 months between doses. 6, 1 This population includes patients with HIV, hematologic malignancies, solid organ transplant recipients, and those on immunosuppressive therapy. 6