Shingles rates are falling sharply in young adults — and the chickenpox vaccine is the likely reason

Among Americans born in the mid-1990s — the first generation eligible for routine childhood chickenpox vaccination — shingles diagnoses are running at less than half the rate of the generation just before them. A large new analysis of electronic health records, released October 2 by Epic Research, puts a number on that gap: a 62% drop between people born from 1991 to 1995 and those born from 1996 to 2000, the sharpest decline between any two adjacent birth-year groups in the dataset.

The analysis drew on records from more than 85 million U.S. adults in the Cosmos dataset — compiled from 2,200 hospitals and more than 50,000 clinics across all 50 states, plus Canada, Lebanon, and Saudi Arabia. Two independent teams, each made up of a clinician and a research scientist, examined the data from different angles and reached similar conclusions.

Our data suggest that trend is now reversing in the very youngest adults, the first generation eligible to be vaccinated against chickenpox as children.— Kersten Bartelt, registered nurse and lead author, Epic Research

Shingles — formally herpes zoster — is caused by the reactivation of the varicella-zoster virus, the same pathogen responsible for chickenpox. After a chickenpox infection, the virus lies dormant in nerve tissue and can re-emerge decades later as a painful, blistering rash, typically on one side of the body. About one in three Americans develops shingles in their lifetime, with risk rising steeply with age. NBC News has reported that complications can include postherpetic neuralgia, a severe and lasting nerve pain, as well as blindness when the outbreak affects the area around the eye, a 20% greater risk of cognitive decline, and elevated risks of stroke and heart disease.

In 1995, the Food and Drug Administration approved the first chickenpox vaccine, which was incorporated into the childhood vaccination schedule that same year. Starting in 1997, states made the vaccine a requirement for children entering school or daycare. Since then, chickenpox infections have fallen by 97%, according to the CDC, as reported by NBC News. The logic of the new Epic findings is straightforward: if the vaccine prevents the initial chickenpox infection, the virus never gets the chance to go dormant — and therefore cannot reactivate as shingles years later.

The numbers bear that out in generational terms. Among all adults tracked from January 2019 to June 2026, shingles diagnoses rose steeply with age — from 6.9 per 10,000 among those born from 2006 to 2008, up to 181.9 per 10,000 among those born from 1968 to 1975, roughly 26 times higher. The rate at the 1991–1995 to 1996–2000 boundary — 45.5 dropping to 17.3 per 10,000 — stands out because it is far larger than the step between any other adjacent cohorts, and it aligns precisely with when routine vaccination began.

The time-series view tells a similar story. Between 2019 and 2026, shingles rates among adults aged 25 to 29 dropped by more than half — falling from 7.7 per 10,000 women and 7.5 per 10,000 men to 3.2 and 3.0, respectively. Rates also fell in the 18-to-24 and 30-to-34 age groups. Among 30-to-34-year-olds, cases dropped from 10.8 to 7.3 per 10,000 for women and from 11 to 7.3 for men.

One important caveat: Epic's report explicitly states that it 'did not evaluate whether patients had received the childhood chickenpox vaccine.' Rather than comparing vaccinated individuals with unvaccinated ones, the analysis looks at differences across birth-year cohorts — that is, across generations. The decline in younger age bands also partly reflects what Epic calls 'cohorts aging in': as the years pass, the 25-to-29 or 30-to-34 age bands are increasingly filled by people born after 1995, so the measured rate naturally shifts toward the post-vaccine generation's lower baseline. Epic also notes that the 1995 rollout included catch-up vaccination for older susceptible children, making the transition gradual rather than a sharp cutoff.

The picture is more complicated for older adults. Among people aged 40 to 49 — who largely experienced natural chickenpox infections as children — shingles rates dipped and then rebounded, reaching about 16 per 10,000 among women aged 45 to 49 by 2026. NBC News reports there is 'no clear evidence' for what is driving the rise in this group. Experts quoted by NBC offered possible explanations: before the vaccine, adults in their 20s, 30s, and 40s were regularly exposed to children with chickenpox, which may have acted as an immune booster. That natural re-exposure has now largely disappeared.

Before the vaccine was available, parents in their 20s, 30s, 40s, and grandparents, were exposed to younger children with chickenpox, so that was like a booster for them.— Dr. Sharon Curhan, physician and epidemiologist, Brigham and Women's Hospital and Harvard Medical School

People who have had the chickenpox virus have a higher risk of developing shingles. People who got the vaccine, while they could get shingles, are at much lower risk.— Dr. Sharon Curhan, physician and epidemiologist, Brigham and Women's Hospital and Harvard Medical School

Epic flags another distortion in the data: the COVID-19 pandemic. Shingles rates are calculated from outpatient visits, meaning the steep drop in routine care during 2020 and 2021 — and the subsequent recovery in patient volume — could push the measured rate down and then back up without reflecting any genuine shift in how often shingles actually occurs. The report says the rebound seen in older age groups 'likely reflects pandemic-era health care use rather than true incidence,' at least in part.

The fundamental open question is durability. Because shingles is rare in people under 50, the current data cannot show whether the protection suggested by these generational patterns will hold as vaccinated millennials and Gen Z adults move into their 50s and 60s — the age range where shingles risk historically surges. Bartelt acknowledged that the data cannot yet prove whether the protection will last as younger cohorts age. A 2022 analysis in the Journal of Infectious Diseases, cited by Epic, found that among people aged 1 to 29, shingles incidence 'later declined in a stepwise pattern once each age group was comprised of persons born in the postvaccine period,' with the authors concluding that their findings do not support earlier modeling predictions that vaccination would push shingles rates higher among adults who had previously had chickenpox.

What the Epic data does establish is a generational signal strong enough — a 62% drop at a single birth-year boundary — to be difficult to explain away. Whether it translates into a lasting reduction in one of the most common and debilitating viral conditions in older Americans will only become clear as the vaccinated generation ages into the decades when shingles typically strikes hardest.

Why it matters — If the generational decline in shingles holds as vaccinated cohorts age into their 50s and 60s — when the disease strikes hardest — the childhood chickenpox vaccine could prove to be one of the more consequential long-term public health interventions of the past three decades.

Reported by nbcnews.com, epicresearch.org, plainlynow.com