Does someone who received the first dose of Shingrix (zoster vaccine) 5 years ago need to restart the series?

Shingrix Vaccination After a Delayed Second Dose

If someone received the first dose of Shingrix 5 years ago, they do NOT need to restart the series but should receive the second dose as soon as possible to complete the vaccination series.

Understanding Shingrix Vaccination Schedule

Shingrix (recombinant zoster vaccine or RZV) is administered as a two-dose series to prevent herpes zoster (shingles). The standard recommendation is:

• First dose at initial visit
• Second dose 2-6 months after the first dose

Delayed Second Dose Considerations

When the second dose is significantly delayed beyond the recommended timeframe:

• The vaccine series does not need to be restarted 1
• The second dose should be administered as soon as possible 1
• The effectiveness of completing the series, even with a delay, is still beneficial 2

Evidence Supporting Completion Rather Than Restart

The National Comprehensive Cancer Network (NCCN) guidelines clearly state that for patients who previously received the first dose of Shingrix, the second dose should be administered to complete the series 1. This recommendation applies regardless of the time elapsed since the first dose.

Research evidence supports this approach:

• A large real-world observational study demonstrated that second doses administered beyond the recommended 6 months did not impair effectiveness 2
• The vaccine effectiveness for two doses (70.1%) was significantly better than for a single dose (56.9%), highlighting the importance of completing the series 2

Clinical Approach for Delayed Second Dose

1. Administer the second dose immediately - Do not restart the series
2. Document completion - Record that the patient has now completed the full vaccination series
3. Patient education - Explain that:
   • The completed series provides better protection than a single dose
   • The delay between doses does not significantly reduce effectiveness
   • No additional doses are required after completing the two-dose series

Special Considerations

• For immunocompromised patients, completing the series is particularly important as they are at higher risk for herpes zoster 3
• Adults ≥50 years benefit significantly from the completed series, with protection against both herpes zoster and postherpetic neuralgia 4

Common Pitfalls to Avoid

1. Unnecessary restart of the series - This wastes resources and exposes the patient to an unnecessary additional dose
2. Assuming a single dose is sufficient - Research shows significantly better protection with two doses (70.1%) compared to one dose (56.9%) 2
3. Delaying the second dose further - While delayed doses are effective, completing the series promptly provides earlier protection

Real-world data shows that approximately 80% of patients complete the two-dose series within 12 months of the initial dose 5, supporting the practice of administering the second dose even after significant delays.