October 01, 2025
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As vaccination rates against HPV rose between 2006 and 2023, infections even among unvaccinated women declined significantly, a new study shows.
Vaccination against the virus that causes cervical cancer is effectively protecting women at high risk for infection who haven't even been vaccinated, a new study said.
This type of effect is called herd immunity, which occurs when enough people in a community are vaccinated against a disease that transmission of it is significantly reduced — and is one of the reasons vaccination is an important measure for public health, the Cleveland Clinic said.
The study published Monday in JAMA Pediatrics tracked the impact of vaccination against the human papillomavirus (HPV) among 2,335 adolescent and young women in Cincinnati between 2006, when the vaccinate first became available, and 2023.
HPV is a common sexually transmitted infection that approximately 80% of sexually active people get at some point in their lives. It is the primary cause of cervical cancer and is also linked to vaginal cancer, penile cancer, anal cancer and genital warts, among other diseases. HPV accounts for nearly 700,000 new cancer cases a year, the International Agency for Research on Cancer said.
But the Cleveland Clinic said HPV vaccination protects against 90% of cervical, anal and most throat cancers.
The new research found that as vaccination rates increased from 0% to 82% over the 17-year study period, infection rates from different strains of HPV fell by between 75% and 98%.
"Our analysis of the data indicates that those reductions in infection rates were primarily due to the vaccine's introduction and not because of changes in sexual behavior or other factors," Aislinn DeSieghardt, clinical research coordinator at Cincinnati Children's Hospital Medical Center and the study's author, said in a press release.
The study found infection rates from two different strains of HPV also had significant reductions — between 72% and 76% — among unvaccinated women, showing evidence of herd immunity.
Increasing vaccination rates, including among boys, may partly account for the evidence of herd immunity, the researchers said.
Participants who were characterized as vaccinated had at least one dose of any of the available vaccines against HPV. The Centers for Disease Control and Prevention recommends people ages 9 to 45 get one of three available shots.
