BACKGROUND AND PURPOSE:

• High-grade cervical lesions (CIN2+) are used to monitor HPV vaccine impact, since they develop much more quickly after infection
• McClung et al. (MMWR, 2019) used data from the Human Papillomavirus Vaccine Impact Monitoring Project (HPV-IMPACT) to assess the impact of the HPV vaccination program
• The following is the first estimate of the number of CIN2+ cases in the U.S. based on population since introduction of the HPV vaccine

METHODS:

• Data review and analysis (2008 to 2016)
  • Data set: HPV-IMPACT
  • A population-based CIN2+ surveillance system
• Data analysis
  • Age-specific rates applied to U.S. population data to estimate the total number of CIN2+ cases

RESULTS:

• An estimated 76% of CIN2+ cases were attributable to HPV types targeted by the vaccine currently used in the US (9-valent HPV vaccine)
• The number of CIN2+ cases diagnosed in women aged 18–29 years decreased from 2008 to 2016
  • 2008: ~216,000 (95% CI, 194,000–241,000)
  • 2016: ~196,000 (95% CI, 176,000–221,000)
• From 2008 to 2016, the rate of CIN2+ per 100,000 women in the US
  • Declined significantly in women aged 18–19 years and 20–24 years
  • Increased significantly in women aged 40–64 years

CONCLUSION:

• Rates of cervical precancers have declined in younger women since the introduction of the vaccine
• A majority of CIN2+ cases diagnosed are attributable to HPV types that the vaccine targets
• These changes are likely due to updated cervical cancer screening and management recommendations, and primary prevention through HPV vaccination
• Increasing coverage of the vaccine in females at the routine age of 11-12 years and catch-up vaccination through women 26 years of age will likely contribute to a further reduction in cervical precancers

Learn More – Primary Sources:

Estimated Number of Cases of High-Grade Cervical Lesions Diagnosed Among Women — United States, 2008 and 2016