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Early HPV Vaccination is Important in Reducing HPV 16/18 Prevalence

, by Elise Tookmanian, Ph.D.

An Asian girl smiles while she receives a vaccine in her shoulder.
Credit: SELF x American Academy of Pediatrics Vaccine Photo Project

Using data from the National Health and Nutrition Examination Survey (NHANES), researchers in the Clinical Genetics (CGB) and Biostatistics Branches (BB) found that vaccine-eligible females who were vaccinated before sexual debut had a greater reduction in HPV 16/18 prevalence than those who were vaccinated after sexual debut or never vaccinated. These findings were published in JAMA Network Open on October 21, 2022.  

Routine HPV vaccination is recommended between the ages of 9 and 12 to protect against the HPV types most highly associated with cervical cancer, HPV 16/18. Researchers, led by Didem Egemen, Ph.D., CGB statistician, and Li C. Cheung, Ph.D., Earl Stadtman tenure-track investigator in BB, used NHANES data to determine the effects of vaccination delay on HPV 16/18 prevalence. For females who were ever-eligible for vaccination (<26 years of age in 2006), the prevalence of HPV 16/18 was six percent for those who were never vaccinated. The prevalence of HPV 16/18 was reduced by 41 percent to three percent for those who were vaccinated after sexual debut and was further reduced by 89 percent to less than one percent for those vaccinated before sexual debut. Crucially, by vaccinating before sexual debut instead of after sexual debut, the HPV 16/18 prevalence was reduced by 82 percent. Among females who were eligible for routine vaccination and received the vaccine, the average age of first vaccine dose was 14.5 years, with only 59 percent receiving their first dose before sexual debut. There were no major differences in vaccine uptake and timing of first dose between racial and ethnic groups.  

These findings highlight the importance of timely HPV vaccination, particularly before sexual debut and at the recommended ages (9-12 years of age).  


Egemen, D, et al. "Variation in Human Papillomavirus Vaccination Effectiveness in the US by Age at Vaccination." JAMA Network Open. 2022. DOI: 10.1001/jamanetworkopen.2022.38041