A large analysis of U.S. electronic health records found a sharp break in shingles diagnoses among adults born around the start of routine childhood chickenpox vaccination, offering population-level evidence consistent with a long-term benefit of the program.
Epic Research examined records from more than 85 million adults and reported that 45.5 per 10,000 people born from 1991 through 1995 had a shingles diagnosis during the study period, compared with 17.3 per 10,000 among those born from 1996 through 2000. That 62% decline was the largest change between any adjacent birth cohorts in the analysis.
What the analysis found
Shingles, also called herpes zoster, occurs when the varicella-zoster virus reactivates after an earlier chickenpox infection. Risk rises strongly with age, and the study reflected that pattern: diagnosis rates ranged from about 6.9 per 10,000 among adults born from 2006 through 2008 to 181.9 per 10,000 among those born from 1968 through 1975.
The United States introduced routine childhood varicella vaccination in 1995. The steepest cohort-to-cohort drop appeared at roughly that transition, when children increasingly reached adulthood without having had wild-type chickenpox.
A separate time-trend analysis found new shingles diagnoses fell among adults ages 18 to 35 from 2019 through mid-2026. Among people ages 25 to 29, the rate declined by more than half to about 3 per 10,000 by 2026. Rates rose among adults ages 40 to 49 after a pandemic-era dip.
The study cannot prove cause and effect
The researchers did not verify whether individual patients received the childhood chickenpox vaccine. That means the birth-cohort pattern is consistent with—but does not by itself prove—that vaccination caused the decline.
The report also notes that disrupted medical visits and the shift toward telehealth during 2020 and 2021 may distort measured trends. Its rates are based on diagnoses recorded during health-care encounters, not active surveillance of every infection in the population.
Epic Research said two independent teams, each including a clinician and research scientist, reached similar conclusions. The data came from Cosmos, which combines records from participating health systems.
What current guidance says
This analysis does not change vaccination recommendations. The Centers for Disease Control and Prevention recommends shingles vaccination for adults 50 and older and for immunocompromised adults 19 and older. Parents and patients should consult their clinicians about age-appropriate vaccination rather than treating a population study as individualized medical advice.
Epic Research published its detailed methods and findings on Oct. 2. The CDC explains shingles symptoms, risks and prevention.
Follow AskNovus Health News for evidence-based updates.
Featured image credit: maks_d/Unsplash. The image is illustrative and does not depict the study or a shingles vaccine.