HPV Type-Specific Prevalence a Decade after the Implementation of the Vaccination Program: Results from a Pilot Study.

Clara Fappani,Elisabetta Tanzi,Fabio Petrelli,Daniela Colzani,Antonella Amendola,Donatella Panatto,Maria Gori,Iolanda Grappasonni,Daniela Amicizia,Silvia Bianchi,Stefania Scuri

doi:10.3390/vaccines9040336

Abstract

Human papillomavirus infection is a cause of the development of invasive cervical cancer. Three types of vaccine are currently available to prevent precancerous/cancerous lesions due to persistent infection, which is supported mainly by 7 different high-risk genotypes. The aim of this pilot study was to acquire preliminary data on type-specific prevalence 10 years after the implementation of the HPV vaccination program in Italy, in order to subsequently plan appropriate observational studies in the Italian population. First-voided urine samples were collected from 393 consenting subjects, both females and males, aged 18–40 years, and HPV DNA was detected by PCR amplification of a 450 bp L1 fragment. All amplified products were genotyped by means of the Restriction Fragment Length Polymorphism (RFLP) method. The female population was divided into three cohorts (“vaccine-eligible”, “pre-screening” and “screening” cohorts) according to the preventive intervention scheduled by age; males were included in the same three cohorts according to their year of birth. The overall prevalence of HPV infection was 19%, being higher in females than in males (22.1% vs. 13.6%, p = 0.03729). In the female population, 10 years after the start of the national immunization program, we observed a reduction in the prevalence of vaccine types and the number of circulating genotypes, especially in the “vaccine-eligible” cohort. The frequency of HPV vaccine types increased with age, particularly in males in the “pre-screening” and “screening” cohorts. Our study highlights the importance of monitoring HPV infection in both genders, to validate the effect of the HPV vaccination program.

Highlights

It is well known that human papillomavirus (HPV) infection is the most common sexually transmitted infection worldwide [1,2]
Females were divided into three cohorts according to their status regarding the prevention of HPV-related diseases: a vaccine-eligible cohort, which consisted of girls born between 1997 and 2001 and belonging to the first vaccination target cohort; a pre-screening cohort, comprising females born between 1991 and 1996, who were still too young to be Vaccines 2021, 9, 336 called for a Pap test; and a screening cohort, consisting of girls born before 1990, who were eligible for a Pap test screening call
Of the 393 participants, 75 (19.08%, 95% confidence interval (95% CI): 15.43–23.2) tested HPV DNA-positive: 56 of the 253 (22.13%, 95% CI: 17.34–27.56) females and 19 of the 140 (13.57%, 95% CI: 8.62–20.01) males (p = 0.03729)

Summary

Introduction

It is well known that human papillomavirus (HPV) infection is the most common sexually transmitted infection worldwide [1,2]. Soon after their first sexual experience, the majority of women acquire the HPV infection, which is generally transient and resolves without symptoms. Persistent infection can cause a wide range of diseases, including benign lesions, precancerous lesions and cancers, in both women and men [3]. HPV DNA is found in almost 100% of cervical cancer samples, and there is a consensus that persistent high-risk HPV infection is a necessary cause of cervical cancer [7,8]. HPV16 is detected in about 90% of HPV-related anal, vaginal, vulvar, penile and oropharyngeal cancers [9]

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