There’s a new shingles shot called HZ/su that works almost just as well for everyone over 50—whether they’re 50 or 80—while the old one, Zostavax, gets much less effective the older you are.
Evidence Quality Assessment
Claim Status
appropriately stated
Study Design Support
Design supports claim
Appropriate Language Strength
definitive
Can make definitive causal claims
Assessment Explanation
The claim cites specific efficacy percentages (96.6%–97.9%) derived from large, randomized, placebo-controlled phase 3 trials (e.g., ZOE-50 and ZOE-70 studies) that directly compared HZ/su and Zostavax across age strata. These trials had sufficient power to detect age-related differences in efficacy, and the results were consistent and statistically robust. The use of definitive language is justified because the data show near-complete protection in all age groups for HZ/su and a clear, documented decline for Zostavax. No overstatement is present; the numbers are directly reported in peer-reviewed publications (e.g., NEJM).
More Accurate Statement
“The adjuvanted herpes zoster subunit vaccine (HZ/su) maintains high efficacy (96.6% to 97.9%) in preventing herpes zoster across all age groups aged 50 and older, including those 70 years and older, as demonstrated in randomized controlled trials, whereas the live-attenuated Zostavax vaccine exhibits a significant age-dependent decline in efficacy.”
Context Details
Domain
medicine
Population
human
Subject
The adjuvanted herpes zoster subunit vaccine (HZ/su)
Action
maintains high efficacy
Target
across all age groups aged 50 and older, including those 70 years and older, contrasting with the age-dependent decline seen in the live-attenuated Zostavax vaccine
Intervention Details
Gold Standard Evidence Needed
According to GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this specific claim, ordered from strongest to weakest evidence.
Evidence from Studies
Supporting (1)
Efficacy of an adjuvanted herpes zoster subunit vaccine in older adults.
This study found that the new shingles vaccine works almost equally well in people aged 50, 60, and even 70+, unlike the old one that worked worse in older people.