BACKGROUND AND PURPOSE:

• HPV vaccine has been shown to be effective at preventing high-grade cervical lesions
  • However, direct effect of quadrivalent HPV vaccine on the risk of invasive cervical cancer remains limited
• Lei et al. (NEJM, 2020) used a large cohort to examine the association between HPV vaccination and the risk of invasive cervical cancer

METHODS:

• Cohort study
• Participants
  • Girls and women
  • 10 to 30 years
  • Living in Sweden (from 2006 to 2017)
• Study design
  • Received at least one dose of vaccine
  • Analysis controlled for
    • Age at follow-up | Calendar year | County of residence | Parental characteristics (education, household income, mother’s country of birth, and maternal disease history)
• Primary outcome
  • Invasive cervical cancer

RESULTS:

• 1,672,983 girls and women included
• Cervical cancer diagnoses
  • Women who received the HPV vaccine: 19 diagnoses
  • Women who had not received the HPV vaccine: 538 diagnoses
• Cumulative incidence of cervical cancer
  • Received vaccination: 47 cases per 100,000 persons
  • Did not receive vaccination: 94 cases per 100,000 persons
• Women who were vaccinated were 0.51 times less likely to experience cervical cancer compared to controls (adjusted for age at follow-up)
  • Incidence rate ratio (IRR) 0.51 (95% CI, 0.32 to 0.82)
  • After additional adjustment for other covariates, IRR was 0.37 (95% CI, 0.21 to 0.57)
• IRR following adjustment for all covariates
  • Vaccinated <17 years
    • IRR 0.12 (95% CI, 0.00 to 0.34)
  • Vaccinated at 17 to 30 years
    • IRR 0.47 (95% CI, 0.27 to 0.75)

CONCLUSION:

• In Sweden, quadrivalent HPV vaccination among women ages 10 to 30 was associated with reduced risk of invasive cervical cancer
• If vaccination initiated <17 years of age, the risk for cervical cancer was 88% lower vs the cohort that had never been vaccinated | Based on the confidence interval, the plausible risk was 66 to 100% lower with vaccination
• The authors conclude

HPV vaccination was associated with a substantially reduced risk of invasive cervical cancer

Learn More – Primary Sources:

HPV Vaccination and the Risk of Invasive Cervical Cancer

Related ObG Topics:

HPV Vaccines: Cochrane Reviews Looks at the Evidence with Multi-Year Follow-Up

The HPV Vaccine Leads to a Reduction in Cervical Precancers in Young Women in the U.S.

How has HPV Prevalence Changed Since Introduction of Vaccine?