# Sustained impact of bivalent HPV immunisation on CIN incidence over two rounds of cervical screening

## TL;DR

This study shows that the bivalent HPV vaccine remains effective for several years, especially in younger women and those from deprived areas.

## Contribution

The study provides real-life longitudinal evidence of the bivalent HPV vaccine's sustained effectiveness over time.

## Key findings

- Vaccine effectiveness against CIN2+ was 72.6% in 12–13-year-olds and 63.2% in 14–16-year-olds.
- Herd protection was observed in all immunized cohorts, with the most deprived women showing the greatest reduction in CIN.
- No benefit was found for vaccination in women over 18 years of age.

## Abstract

Vaccination against high‐risk HPV has been shown to reduce significantly the incidence of pre‐invasive and invasive cervical disease. Clinical trials show immunity and vaccine effectiveness for over 12 years but real‐life longitudinal data are lacking. Vaccination with the bivalent vaccine (3 dose schedule) for women aged 12–18 years began in Scotland in 2008; immunised women entered screening in 2010. Women immunised at age12–13 years entered screening in 2015. Linked data from ≤12 years of routine screening activity shows adjusted VE against CIN2+ at age 12–13 of 72·6% (95%CI: 67.7–76.8) and at age 14–16 of 63·2 (CI 60·4–65·8), and against CIN3+ of 81·7 (CI 76·2–78·6; age 12–13) and 68·1 (CI 64·1–71·6; age 14–16) after 3 doses or two doses 5 months apart. Adjusted VE following two doses 1 month apart or one dose only at age14 was 20.5 (95%CI: 6.1–32.6) for CIN2+ and 34.9 (95%CI:17.0–48.9) for CIN3+. No benefit was seen with vaccination over the age of 18 years. The most deprived women showed the highest incidence of CIN2+ and CIN3+, and the greatest reduction in CIN2+ and CIN3+ following complete immunisation. Herd protection is seen in all immunised cohorts. This population based analysis confirms the long‐term effectiveness of the bivalent HPV vaccine, greatest in women from the most deprived areas and reinforces the importance of ensuring high vaccine uptake rates at an early age.

While vaccination against high‐risk HPV infection, the primary cause of cervical malignancy, has demonstrated long‐term effectiveness in clinical trials, real‐life longitudinal data are lacking. Here, the authors present linked long‐term screening data on the effectiveness of bivalent HPV vaccination with a minimum follow‐up of 54 months. The results show high vaccine effectiveness against high‐grade cervical intraepithelial neoplasia in women who were vaccinated aged 12–13 years, significant effectiveness in women vaccinated aged 14–16 and 17–18 years with herd protection, and no benefit in women vaccinated over 18. The findings confirm stable protection from bivalent HPV vaccination.