What is the best next step for a 55-year-old male who received only one dose of Shingrix (zoster vaccine recombinant) over a year ago?

Completing the Shingrix Vaccination Series for a 55-Year-Old Male

The best next step for a 55-year-old male who received only one dose of Shingrix over a year ago is to administer the second dose of Shingrix as soon as possible. 1, 2

Rationale for Completing the Series

• Single-dose effectiveness of Shingrix is only 56.9% compared to 70.1% with the complete two-dose series 3
• The FDA-approved Shingrix schedule recommends two doses given 2-6 months apart for optimal protection 2
• Even though more than a year has passed since the first dose, completing the series is still beneficial:
  • There is no evidence that a delayed second dose impairs effectiveness 3
  • The FDA label confirms that second doses administered beyond the recommended 6 months still provide effective protection 2

Efficacy of Complete vs. Incomplete Vaccination

The importance of completing the two-dose series is supported by real-world effectiveness data:

• Two-dose effectiveness: 70.1% (95% CI, 68.6-71.5) 3
• Single-dose effectiveness: 56.9% (95% CI, 55.0-58.8) 3
• Complete series effectiveness against postherpetic neuralgia: 76.0% (95% CI, 68.4-81.8) 3

Administration Considerations

• No need to restart the series - simply administer the second dose 1
• No safety concerns have been identified with delayed administration of the second dose 2
• Most common side effects to anticipate include:
  • Injection site reactions (pain, redness, swelling)
  • Systemic reactions (fatigue, myalgia, headache) 2, 4
  • Most reactions are mild to moderate and resolve within 2-3 days 4

Completion Rates and Adherence

• Real-world data shows approximately 80% of patients complete the two-dose series within 12 months of the first dose 5
• Patient education about the importance of the second dose is critical to ensure optimal protection against herpes zoster and its complications

Special Considerations

• If the patient has developed any new immunocompromising conditions since the first dose, the second dose is still recommended and safe 1, 2
• Shingrix is preferred over the older live zoster vaccine (Zostavax) due to its higher efficacy and non-replicating nature 6, 4

Common Pitfalls to Avoid

1. Restarting the series unnecessarily - There is no maximum interval between doses; simply administer the second dose regardless of time elapsed
2. Withholding vaccination due to mild illness - Minor acute illness is not a contraindication
3. Assuming single-dose protection is adequate - The data clearly shows superior protection with two doses
4. Failing to document the vaccination - Ensure proper documentation to maintain accurate immunization records

Completing the Shingrix series will provide this 55-year-old male with optimal protection against herpes zoster and its complications, particularly postherpetic neuralgia, which can significantly impact quality of life.