An estimated 50,000 people in the United States are diagnosed with a cancer caused by the human papillomavirus (HPV) every year. Nearly half of these (46%) are cervical cancer, almost all of which is caused by HPV, while the others are anal, head and neck (oropharyngeal), vulvar, vaginal, and penile cancers.
There is now, however, a vaccine available to prevent most of the HPV strains at the highest risk for developing into cancer, meaning the number of new HPV-associated cancers could eventually decline in the future with enough HPV vaccination coverage.
Like many other immunizations, the HPV vaccine has been subject to a substantial amount of misinformation about its effectiveness and particularly its safety. The Vaccine Integrity Project recently conducted a systematic review of the literature to date on the vaccine’s safety and effectiveness, and the resulting report is a rich data resource journalists can use in any stories about HPV, the vaccine, or cancers linked to the virus.
Many of those receiving diagnoses of HPV-associated cancers today would not necessarily have been able to prevent those cancers with the vaccine. It takes an estimated 15-20 years for an HPV infection to develop into cancer, and the first vaccine — which prevented only two of the highest-risk HPV strains — was approved in 2006, exactly 20 years ago, and only for females ages 9-26. The vaccine’s indication was eventually expanded to males up to age 26 and is now routinely recommended by the CDC and the American Academy of Pediatrics for all youth ages 9-14.
Since the first approval in 2006, an updated vaccine that protects against an additional seven high-risk strains (in addition to two low-risk strains that cause 90% of genital warts cases) has been approved, and anyone up to age 45 can receive it. As the only vaccine explicitly and successfully developed to prevent cancer, it’s important that journalists have access to the most up-to-date information on the shot’s safety and effectiveness. More than 90% of cervical cancer cases are caused by HPV, and it’s estimated to be responsible for 75% of vaginal cancer, 69% of vulvar cancer, 63% of penile cancer, 91% of anal cancer, and 70% of oropharyngeal cancer.
Vaccine Integrity Project evidence review of HPV vaccine
The new report is a systematic review and meta-analysis of the HPV vaccine’s safety and effectiveness conducted by the Vaccine Integrity Project with funding from the Rockefeller Foundation and additional support from the Alumbra Foundation to the Center for Infectious Disease Research and Policy (CIDRAP) at the University of Minnesota, where the Vaccine Integrity Project was founded. (Other funders of the project can be found here.) This document pulls together all peer-reviewed literature on the vaccine from September 2024 to January 2026, which the authors then combined with the results of two previous Cochrane reviews of studies through September 2024.
Together, the new report covers the full breadth of peer-reviewed literature on HPV vaccines since their inception, including results from 274 studies on safety, effectiveness, and immunogenicity. It covers the original quadrivalent vaccine (Gardasil), the bivalent vaccine that was discontinued due to market pressure (Cervarix), and the current 9-valent vaccine (Gardasil 9). The types of trials included are randomized controlled trials, cohort studies, ecological studies, case-control studies and immunogenicity analyses.
The populations studied are predominantly male and female adolescents, but several studies also include women ages 20-45 and pregnant women.
The report included the following safety outcomes: overall safety and adverse events, adverse pregnancy outcomes, Guillain‐Barré syndrome (GBS), postural orthostatic tachycardia syndrome (POTS), chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME), paralysis, complex regional pain syndrome (CRPS), premature ovarian failure and infertility. Researchers studied several of these outcomes specifically because misinformation inaccurately linked them to the vaccine. The parts of the report addressing POTS, CFS/ME, infertility and premature ovarian failure are particularly helpful for journalists writing about the unsupported claims related to these conditions and the vaccine.
Effectiveness outcomes studied include all HPV-associated cancers, though especially cervical cancer, as well as new HPV infections, HPV infection with HPV16 and HPV18 — the two high-risk strains responsible for most cervical cancer — and high-grade intraepithelial neoplasia, which are the precancerous cells that develop into cancer if not addressed, in the five genital and anal cancers. The two immunogenicity outcomes are seroconversion and antibody neutralization titers, neither of which was in the Cochrane reviews, so that data comes only from September 2024 to January 2026.
Who to talk to
Kevin Griffis at CIDRAP is the best contact for the Vaccine Inegrity Project and its reports.
How to use this data
The data is not set up as a searchable database, but there are two particularly useful parts for journalists. First, each subhead under the safety, effectiveness, and immunogenicity outcomes is organized for easy keyword searching. For example, a journalist can search “POTS” or “pregnancy” and easily find summaries of the evidence for those outcomes.
On page 30, hyperlinks link to specific tables for each outcome category, including study type, population, sample size, key findings, and risk of bias. If you’re seeking a particular study for your article, it’s easy to use a keyword search or skim these tables to find what’s needed.
Story ideas
The best use of this data is as complementary or background data for any stories about the HPV vaccine, HPV infection, or cervical cancer. Here are some evergreen or personal interest stories about these topics that would be appropriate for any market:
- A profile on someone who has or survived cervical cancer, oropharyngeal cancer, or another HPV-linked cancer.
- Stories looking at local HPV rates and/or interventions to improve uptake or address hesitancy related to the vaccine.
- “How scientists know the HPV vaccine does not cause TK” explainers, where TK could be any of the outcomes some people have been concerned are linked to the vaccine.
- Stories focusing on the vaccine’s effectiveness in reducing cervical cancer and dysplasia.
- Stories tracing the history of the vaccine and the shifts in recommendations from three shots to two or one shot in certain populations.
- Stories looking at what evidence gaps exist, such as effectiveness in preventing non-cervical cancers and pre-cancers in males
Additional resources
- The HPV Vaccine: Access and Use in the U.S., KFF, April 2026
- Human papillomavirus and cancer, WHO, March 2024
- Cancers Associated with Human Papillomavirus, CDC, 2025
- Cancers Linked with HPV Each Year, CDC, December 2025
- Evidence review finds HPV vaccines to be safe, extremely effective, CIDRAP, May 2026
