A report in CDC's Morbidity and Mortality Weekly Report*, 2025.*
HPV vaccine was first recommended in the United States in 2006. Since then, vaccination coverage has grown and many young women vaccinated as children or teenagers have reached the age for cervical cancer screening. CDC's surveillance now shows that among screened women aged 20–24, the age group most likely to have been vaccinated, cervical precancers fell by 79% from 2008 to 2022, and higher-grade precancers by 80%.
Background
HPV causes about 10,800 cervical cancers in the United States each year, and cervical cancer is the most common HPV-caused cancer in women. HPV cancers take many years to develop — the median age at diagnosis is 50 — but precancers found by screening can appear within a few years of infection. That makes them an early measure of whether vaccination is working.
- The precancers: cervical intraepithelial neoplasia (CIN) grades 2–3 and adenocarcinoma in situ (AIS), together called CIN2+. CIN3+ means CIN grade 3 and AIS, the stage closest to cancer.
- Screening: the Pap test has long been the main tool; testing for high-risk HPV, usually alongside a Pap test, has become more common over the past decade. Recommended intervals have lengthened from yearly to every 3 years (Pap only) or every 5 years (with an HPV test).
- Vaccination: routine vaccination was first recommended for girls and women in 2006 and for boys and men from 2011. It is now recommended for all children at 11–12 (it can start at 9), with catch-up through 26; since 2019, adults aged 27–45 may decide with their clinician. Two doses are recommended if the series starts before 15, otherwise three. Coverage with at least one dose among 13- to 17-year-olds rose through 2021, then levelled off, reaching 76.8% in 2023.
How CDC tracks it
Since 2008 the Human Papillomavirus Vaccine Impact Monitoring Project (HPV-IMPACT) has recorded every laboratory-confirmed CIN2+ diagnosis among residents of five areas: Alameda County, California; New Haven County, Connecticut; Monroe County, New York; Davidson County, Tennessee; and 28 zip codes in metropolitan Portland, Oregon.
Because how often women are screened changes over time, rates are calculated per 100,000 screened women. The number screened was estimated from census data, insurance claims and survey data, weighted by private, public or no insurance. Data from 2020 were left out of the trend analysis because of pandemic disruptions to care.
What it found
From 2008 to 2022, 39,977 CIN2+ cases were reported, 13,027 (32.6%) of them CIN3+.
| Screened women aged | CIN2+ | CIN3+ |
|---|---|---|
| 20–24 | down 11.0% a year; 2022 rate 79.5% below 2008 | 2022 rate 80.3% below 2008 |
| 25–29 | up 3.1% a year to 2016, down 4.3% a year after; stable overall | down overall (−3.5% a year); 2022 rate 37.2% below 2008 |
| 30–39 | rose to 2016, then fell; small overall increase | similar to CIN2+ |
| 40–64 | increased significantly | similar to CIN2+ |
CIN2+ (top) and CIN3+ (bottom) incidence per 100,000 screened women, by age group, 2008–2022. CDC.
What it means
The biggest declines are in the youngest age group, where the benefit of vaccination would show first — consistent with a considerable impact of the U.S. HPV vaccination program.
- Why 20–24 first: before 2014, women aged 20–24 could only have been vaccinated at catch-up ages (13–26). By 2018–2022, all of them could have been vaccinated at the routine age of 11–12. Vaccinating at that age works better because it usually comes before any exposure to HPV through sexual contact.
- Matching trends: the declines mirror falls in vaccine-type HPV in self-collected swabs, first among girls and women aged 14–19 and then among those aged 20–24.
- A first for ages 25–29: this is the first U.S. evidence of a significant fall in precancers in an older group. Most women aged 25–29 in 2022 could have been vaccinated at 11–12. CIN3+ may have fallen before CIN2+ because a larger share of CIN3+ is caused by HPV16 or HPV18, types the early vaccine targeted.
- Why older rates rose, then eased: earlier increases among women aged 25–39 were put down to longer screening intervals and more HPV testing, which finds more precancers than the Pap test. Those increases reversed or levelled off in 2016–2017, as models predicted when screening switched from Pap to HPV testing. Older women had less chance to benefit, having been eligible only for catch-up vaccination, when many had already been exposed.
Limitations
- The number of women screened was estimated from claims and survey data, which could over- or underestimate rates.
- Changes in screening and treatment guidelines, and uncertainty in classifying lesions, could have affected how many cases were found.
- Trends in populations cannot prove cause, though such analyses are routinely used to judge vaccination programs and no other plausible explanation has been found.
- One site's area was enlarged and screening estimates were standardised, so the numbers cannot be compared directly with the project's earlier reports.
The bottom line
The findings support the Advisory Committee on Immunization Practices' recommendation to vaccinate children against HPV at 11–12, with catch-up through 26. HPV vaccination and cervical cancer screening that follows the guidelines are both important tools for preventing cervical cancer.
Sources
- Julia W. Gargano, Ruth Stefanos, Rebecca M. Dahl and others, for the HPV-IMPACT Working Group, "Trends in Cervical Precancers Identified Through Population-Based Surveillance — Human Papillomavirus Vaccine Impact Monitoring Project, Five Sites, United States, 2008–2022", MMWR, vol. 74, no. 6, 2025. https://www.cdc.gov/mmwr/volumes/74/wr/mm7406a4.htm — supplementary table: https://stacks.cdc.gov/view/cdc/176064
- Rewritten in hubnx's own words.
Licence: CC0 1.0 (public domain) · Adapted from www.cdc.gov
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