Investigator
University Of Copenhagen
Human papillomavirus prevalence in first, second and third cervical cell samples from women HPV-vaccinated as girls, Denmark, 2017 to 2024: data from the Trial23 cohort study
BACKGROUND Danish women vaccinated with the 4-valent human papillomavirus (HPV) vaccine (HPV types: 6/11/16/18) at age 14 in 2008 reached screening age in 2017, allowing assessment of long-term effects on prevalence, persistence and incidence of HPV infections. AIM To examine the HPV status of cervical samples over time among women vaccinated as girls. METHODS Between February 2017 and February 2024, residual material from cytology-analysed samples collected through the ‘Trial23’ study, part of the national screening programme, was tested for HPV16/18 and non-vaccine high-risk (HR) HPV types. Prevalence in first, second and third samples, and persistence and incidence between samples were calculated. RESULTS Over 7 years, 8,659 women provided at least one sample, 5,835 at least two and 2,461 at least three. In 7,800 vaccinated women, HPV16/18 prevalence was 0.4% (95% confidence interval (CI): 0.2–0.5), 0.3% (95% CI: 0.1–0.4) and 0.2% (95% CI: 0.0–0.4) in three consecutive samples. Prevalence of non-vaccine HR HPV was 32% (95% CI: 31–33), 28% (95% CI: 27–29) and 31% (95% CI: 29–33). Persistence of HPV16/18 and non-vaccine HPV among vaccinated women was 40% and 53%. In adjusted analyses comparing vaccinated vs unvaccinated women, incidence was significantly lower for HPV16/18 (adjusted relative risk (aRR) < 0.10) while incidence of non-vaccine HR HPV types was higher (aRR: 1.66; 95% CI: 1.12–2.45). No significant difference was observed for persistence. CONCLUSION Our study provides real-world evidence of stable protection against HPV16/18 infections in women vaccinated as girls. Less intensive screening seems reasonable until women vaccinated with the 9-valent vaccine reach screening age, when screening should be reconsidered.
Cervical cancer incidence in Denmark: Disentangling determinants of time trend
AbstractCervical cancer is a preventable disease. Nevertheless, stagnation has been seen in incidence rates also in countries with well‐functioning healthcare. On this basis, we investigated associations between control interventions and changes in cervical cancer incidence in Denmark from 2009 to 2022. Data on human papillomavirus (HPV)‐vaccination were retrieved from Staten's Serum Institute; on screening recommendations from Danish Health Authority, on screening performance from Danish Quality Database for Cervical Screening; and on cervical cancer incidence from Nordcan and Danish Cancer Register. We reported coverage with HPV vaccination (1+ dose); coverage with cervical cell samples; number of women with primary HPV tests; proportion of non‐normal cell samples without timely follow‐up; number of conizations; and cervical cancer incidence rates. In 2022, all women aged ≤29 had been offered childhood HPV vaccination with coverage of 80%–90%. By 2020–2022, the cervical cancer incidence rate in women aged 20–29 was 3 per 100,000; at level of disease elimination. In 2017, women aged 70+ were offered a one‐time HPV screening, and by 2020–2022, the old‐age peak in cervical cancer incidence had largely disappeared. From 2009 to 2022, proportion of non‐normal cell samples without timely follow‐up decreased from 20% to 10%, and conventional cytology was largely replaced by SurePath liquid‐based cytology; these factors could explain the steady decrease in cervical cancer incidence rate. Implementation of primary HPV screening in women aged 30–59 in 2021 was reflected in a, probably temporary, increase in the 2022 cervical cancer incidence rate. In conclusion, combined interventions with childhood HPV vaccination; one‐time HPV screening of elderly women; and better management of screening broke previous stagnation in cervical cancer incidence rate.
