Suspension of proactive recommendations for HPV vaccination has led to a significant increase in HPV infection rates in young Japanese women: real-world data

Abstract Background Vaccination against human papillomavirus (HPV) has proven to be effective against severe cervical lesions and genital warts, whereas no previous study has provided real-world data on the HPV vaccine effectiveness against high-grade vulvovaginal lesions. Methods A cohort of all women aged 17–26 years, living in Denmark during 2006–2019 was followed in nationwide registers for individual-level information about HPV vaccination and first diagnoses of vulvar and vaginal high-grade intraepithelial lesions or worse (HSIL+). The cumulative incidence of vulvar and vaginal HSIL+, respectively, was estimated with the Aalen-Johansen estimator and Cox proportional hazards regression was used to estimate hazard ratios (HRs) for vulvar and vaginal lesions separately comparing women vaccinated at age <16 years and at age 17–26 years with unvaccinated women. Results The cohort consisted of 514,537 women, of which 50.6% were vaccinated at baseline (<16 years), 31.8% were vaccinated during follow-up (17–26 years) and 17.6% remained unvaccinated. The cumulative incidence was less than 0.6‰ for vulvar HSIL+ and less than 0.2‰ for vaginal HSIL+. Adjusted analyses showed reduced hazard rates for both vulvar (HR = 0.22, 95% CI = 0.13 to 0.38) and vaginal HSIL + (HR = 0.16, 95% CI = 0.04 to 0.55) for women vaccinated at age ≤16 years compared to unvaccinated women. For women vaccinated at 17–26 years, the reductions in hazard rates were smaller for vaginal HSIL+ and close to zero for vulvar HSIL+. Conclusion HPV vaccination before 17 years of age reduces the risk of vulvar and vaginal HSIL+ based on real-world data.

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Median age at HPV infection among women in the United States: A model-based analysis informed by real-world data

Open Forum Infectious Diseases ◽

10.1093/ofid/ofab111 ◽

2021 ◽

Author(s):

Vimalanand S Prabhu ◽

Craig S Roberts ◽

Smita Kothari ◽

Linda Niccolai

Keyword(s):

Natural History ◽

Real World ◽

Clinical Decision Making ◽

Age Distribution ◽

The United States ◽

Hpv Infection ◽

Real World Data ◽

World Data ◽

Model Based ◽

Model Based Analysis

Abstract Background The US Advisory Committee for Immunization Practices (ACIP) recommended shared clinical decision-making for HPV vaccination of individuals aged 27 to 45 years (mid-adults) in June 2019. Determining the median age at causal HPV infection and CIN2+ diagnosis based on the natural history of HPV disease can help better understand the incidence of HPV infections and the potential benefits of vaccination in mid-adults. Methods Real-world data on CIN2+ diagnosis from the pre-vaccine era were sourced from a statewide surveillance registry in Connecticut. Age distribution of CIN2+ diagnosis in 2008 and 2009 was estimated. A discrete-event simulation model was developed to predict the age distribution of causal HPV infection. The optimal age distribution of causal HPV infection provided the best goodness-of-fit statistic to compare the predicted vs real-world age distribution of CIN2+ diagnosis. Results The median age at CIN2+ diagnosis from 2008 through 2009 in Connecticut was 28 years. The predicted median age at causal HPV infection was estimated to be 23.9 years. There was a difference of 5.2 years in the median age at acquisition of causal HPV infection and the median age at CIN2+ diagnosis. Conclusions Real-world data on CIN2+ diagnosis and model-based analysis indicate a substantial burden of infection and disease among women aged 27 years or older, which supports the ACIP recommendation to vaccinate some mid-adults . When natural history is known, this novel approach can also help determine the timing of causal infections for other commonly asymptomatic infectious diseases.

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