Delaying vaccination until after first sexual activity was associated with higher prevalence of vaginal human papillomavirus.

The US Advisory Committee on Immunization Practices recommends that adolescents receive routine human papillomavirus (HPV) vaccination between ages 9 and 12 years to prevent cervical cancer; however, vaccination frequently occurs later, often after first sexual activity. A national health interview database that includes vaginal HPV testing data was used to assess the prevalence of high-risk HPV subtypes (16/18) in 4727 women (mean age, 18 years). By the time of this assessment, all participants already had been eligible for HPV vaccination – either routinely at ages 9 to 12 years or on a ‘catch-up’ basis, at ages 13 to 26 years.

Only 56% of women were ever vaccinated, and only 21% of those were vaccinated by age 12 years. Among vaccinated women, 59% were vaccinated before first sexual activity and 41% after. The presence of vaginal HPV-16/18 in unvaccinated women was 6%, compared with 3% in those vaccinated after first sexual activity and 1% in those vaccinated before first sexual activity.

Comment: The rate of vaccination by age 12 years in this study was quite low (12%), and the rate before first sexual activity was only modestly better at 33%. By encouraging HPV vaccination at young ages with a two-dose series, we can improve vaccination rates prior to first sexual activity, eliminate most cervical cancer and address the rising rates of HPV-related head and neck cancer. Waiting until after age 15 years requires a three-dose series, which might help persuade hesitant adolescents and parents to vaccinate earlier.
THOMAS L. SCHWENK, MD
Professor Emeritus, Family and Community Medicine, University of Nevada School of Medicine, Reno, USA.

Egemen D, et al. Variation in human papillomavirus vaccination effectiveness in the US by age at vaccination. JAMA Netw Open 2022; 5: e2238041.

This summary is taken from the following Journal Watch title: Infectious Diseases.