I’m an adult who isn’t sure if I’ve received two shingles vaccine doses; should I get the recombinant zoster vaccine (Shingrix) now?

Proceed with the Full 2-Dose Shingrix Series Now

If you're uncertain whether you completed the Shingrix series, you should receive the full 2-dose series starting immediately—there is no harm in revaccination, and this ensures you have optimal protection against shingles. 1

Why This Approach Is Recommended

The CDC and American College of Physicians explicitly state that adults with uncertain vaccination history should receive the complete 2-dose Shingrix series without delay. 1 This recommendation prioritizes your protection over the theoretical concern of "extra" doses, because:

• No safety concerns exist when administering Shingrix to someone who may have already received one or both doses—the vaccine has an excellent safety profile with no documented harm from additional doses. 1, 2
• Attempting to verify your vaccination history through medical records or antibody testing would delay protection and is not recommended by guidelines. 1
• Incomplete vaccination leaves you vulnerable—if you only received one dose previously, you lack the full 97.2% efficacy that the 2-dose series provides. 3

The Vaccination Schedule

• Give the first dose immediately, then administer the second dose 2-6 months later (minimum interval: 4 weeks). 1, 3
• The standard schedule for immunocompetent adults is doses at 0 and 2-6 months. 1

Why Shingrix Requires Two Doses

• Single-dose efficacy is inadequate—the clinical trials that demonstrated 97.2% efficacy against herpes zoster required both doses. 3
• Protection is sustained for at least 8 years with minimal waning when the full 2-dose series is completed, maintaining efficacy above 83.3%. 1
• Even if you received one dose years ago, completing the series now will restore full protection. 1

Common Pitfalls to Avoid

• Don't delay vaccination to search for old records—guidelines explicitly recommend proceeding with vaccination when history is uncertain. 1
• Don't assume one dose is sufficient—this is the most common error, as many patients mistakenly believe a single dose provides adequate protection. 1
• Don't confuse Shingrix with the older Zostavax vaccine—if you received Zostavax (the live vaccine given as a single shot) in the past, you still need the full 2-dose Shingrix series because Zostavax efficacy drops to only 14.1% by year 10. 1, 4

What to Expect After Vaccination

• Injection-site reactions are common (pain, redness, swelling), occurring in 9.5% as grade 3 reactions compared to 0.4% with placebo. 1
• Systemic symptoms (fever, fatigue, myalgia) occur in 11.4% of recipients versus 2.4% in placebo recipients, but these are transient and mild-to-moderate. 1, 2
• No serious safety concerns have been identified in large clinical trials, with similar rates of serious adverse events between vaccine and placebo groups. 1, 2

Why This Matters for Your Health

• Shingles affects 1 in 3 adults in their lifetime, with risk increasing substantially after age 50. 4
• Postherpetic neuralgia (PHN)—chronic, debilitating nerve pain—is the most feared complication, and Shingrix prevents this in 85.5% of cases. 3
• Breakthrough cases are milder—even the 3% who develop shingles despite vaccination experience less severe disease and lower rates of PHN. 5