The impact of human papillomavirus type on colposcopy performance in women offered HPV immunisation in a catch-up vaccine programme: a two-centre observational study.

OBJECTIVE: To determine whether human papillomavirus (HPV) immunisation has affected the prevalence of HPV genotypes and colposcopic features of cervical intraepithelial neoplasia (CIN) in young women referred for colposcopy. DESIGN: A two-centre observational study including vaccinated and unvaccinated women. SETTING: Colposcopy clinics serving two health regions in Scotland, UK. POPULATION: A total of 361 women aged 20-25 years attending colposcopy following an abnormal cervical cytology result at routine cervical screening. METHODS: Cervical samples were obtained from women for HPV DNA genotyping and mRNA E6/E7 expression of HPV 16, 18, 31, 33, and 45. Demographic data, cytology, and histology results and colposcopic features were recorded. Chi-square analysis was conducted to identify associations between vaccine status, HPV genotypes, and colposcopic features. MAIN OUTCOME MEASURES: Colposcopic features, HPV genotypes, mRNA expression, and cervical histology. RESULTS: The prevalence of HPV 16 was significantly lower in the vaccinated group (8.6%) compared with the unvaccinated group (46.7%) (P = 0.001). The number of cases of CIN2+ was significantly lower in women who had been vaccinated (P = 0.006). The HPV vaccine did not have a statistically significant effect on commonly recognised colposcopic features, but there was a slight reduction in the positive predictive value (PPV) of colposcopy for CIN2+, from 74% (unvaccinated) to 66.7% (vaccinated). CONCLUSIONS: In this group of young women with abnormal cytology referred to colposcopy, HPV vaccination via a catch-up programme reduced the prevalence of CIN2+ and HPV 16 infection. The reduced PPV of colposcopy for the detection of CIN2+ in women who have been vaccinated is at the lower acceptable level of the UK national cervical screening programme guidelines. TWEETABLE ABSTRACT: Reduction of hrHPV positivity and CIN in immunised women consistent with lower PPV of colposcopy for CIN2+.