As reported in The Lancet by Falcaro et al, a register-based observational study has shown that the England national human papillomavirus (HPV) vaccine program, initiated in 2008 using a bivalent vaccine (Cervarix; HPV16/18), has been successful in reducing the rates of cervical cancer and grade 3 cervical intraepithelial neoplasia (CIN3) in young women.
Study Details
The program was initiated in 2008 with routine vaccination offered to girls aged 12 to 13, with a catch-up program for those aged 14 to 18 in 2008 to 2010. Data from a population-based cancer registry were assessed for diagnoses of cervical cancer and CIN3 between January 2006 and June 2019 in women aged 20 to 64. Relative risks of cancer and CIN3 were assessed in three cohorts by age at which vaccination was offered vs earlier cohorts that were not eligible for vaccination.
Key Findings
The analysis included data from a total of 13.7 million-years of follow-up among women aged 20 to 30.
Estimated relative reductions in cervical cancer rates by age at vaccine offer were 34% (95% confidence interval [CI] = 25%–41%) for age 16 to 18 (school year 12–13), 62% (95% CI = 52%–71%) for age 14 to 16 (school year 10–11), and 87% (95% CI = 72%–94%) for age 12 to 13 (school year 8) compared with the reference unvaccinated cohort.
Estimated relative reductions in CIN3 rates by age at vaccine offer were 39% (95% CI = 36%–41%) for age 16 to 18, 75% (95% CI = 72%–77%) for age 14 to 16, and 97% (95% CI = 96%–98%) for age 12 to 13.
Among those offered vaccination at age 12 to 13, the crude incidence rates were 0.3/100,000 women-years for cervical cancer and 2.0/100,000 women-years for CIN3.
It was estimated that by the end of June 2019, there had been 448 (95% CI = 339–556) fewer-than-expected cervical cancers and 17,235 (95% CI = 15,919–18,552) fewer-than-expected cases of CIN3 in vaccinated cohorts compared with the most recent unvaccinated cohort.
The investigators concluded: “We observed a substantial reduction in cervical cancer and incidence of CIN3 in young women after the introduction of the HPV immunization program in England, especially in individuals who were offered the vaccine at age 12–13 years. The HPV immunization program has successfully almost eliminated cervical cancer in women born since [September] 1, 1995.”
Peter Sasieni, PhD, of Innovation Hub, Guy’s Cancer Centre, Guy’s Hospital, London, is the corresponding author ofThe Lancet article.
Disclosure: The study was funded by Cancer Research UK. For full disclosures of the study authors, visit www.thelancet.com.
