Skip to Main Content

Human Papillomavirus Vaccine Impact Monitoring Project Across CT (HPV-IMPACT)


HPV is the primary cause of cervical cancer. It has also been shown to be responsible for several other cancers as well, causing significant morbidity and mortality. In 2006, the FDA licensed a quadrivalent vaccine that protects against four types of HPV (6, 11, 16, 18). HPV types 16 and 18 are responsible for approximately 70% of cervical cancers. HPV types 6 and 11 are the main cause of genital warts. In 2014, a nine-valent vaccine became available. In addition to the four types of HPV that were covered in the quadrivalent vaccine, the nine-valent vaccine protects against five additional cancer-causing types of HPV (31, 33, 45, 52, 58) that are associated with another 20% of cervical cancers. In 2008, HPV-IMPACT began collecting data to study the impact of HPV vaccination on high-grade cervical lesions (HGCLs). HGCLs are pre-cancerous lesions that can develop into cancer if not detected and treated in time. In addition, HPV-IMPACT collects data on invasive cervical cancer in collaboration with the Connecticut Tumor Registry.


This project aims to monitor the impact of HPV vaccination on population health by tracking both HGCLs and cervical cancer. HGCLs occur in greater numbers and develop over a shorter time frame than cervical cancer, making them an efficient endpoint when examining vaccine effectiveness. In addition, these lesions are important because they can incur substantial morbidity, treatment costs, and psychological stress. The goal of HPV vaccination is to greatly reduce the number of cervical cancer cases.

Goals & Objectives

  • Monitor HPV vaccination impact on trends in incidence of HGCLs also known as cervical intraepithelial neoplasia (CIN) grades 2 and 3 adenocarcinoma in situ (AIS) and cervical cancer, collectively known as CIN2+.
  • Monitor HPV vaccination impact on HPV types associated with CIN2+.
  • Improve public health practice through local population-based surveillance of HPV-related CIN2+
  • Estimate cervical cancer screening rates in Connecticut.
  • Estimate vaccine effectiveness


  • Statewide passive monitoring of CIN2+ diagnoses from pathology laboratories
  • Population-based active surveillance CIN2+ in New Haven county (2008-2023); Naugatuck Valley and South Central Council of Governments (2024-ongoing)
  • Enhanced data collection through patient interviews and medical record reviews to determine HPV vaccination status
  • Specimen collection to determine HPV genotype associated with CIN2+ diagnoses
  • Laboratory and healthcare provider surveys
  • Estimation of cervical cancer screening in Connecticut
  • Analyses of population databases for other HPV indicators such as anogenital warts

Contributions from students at Yale and other universities

  • Potential Impact of Covid-19-Related Disruptions to Cervical Cancer Screening on Future Disease Burden: A Modeling Study. Guinevere Oliver (2022) MPH Thesis. Yale School of Public Health.
  • Geospatial Analysis of High-Grade Cervical Lesions to Address Health Disparities. Savanah Russ (2019) MPH Thesis. Yale School of Public Health.
  • Increasing Human Papillomavirus Vaccine Uptake in Adolescents: A Targeted Intervention Approach. AmberJean Hansen (2016) MPH Capstone. University of New England.
  • Trends in HPV 16/18-Associated Cervical Lesions in New Haven County, Connecticut, 2008-2014. Susan Hannagan (2016) MPH Thesis. Yale School of Public Health.
  • Sociodemographic Differences in Human Papillomavirus Vaccine Impact: a Systematic Review. Alexandra Montano (2016) MPH Thesis. Yale School of Public Health.
  • Spatial Distribution of High Grade Cervical Lesions in Connecticut, 2008-2013. Aref Seno (2015) MPH Thesis. Yale School of Public Health.
  • Provider Survey to Identify Pathology Laboratories, 2015. Adam Misiorski (2015) Undergraduate Internship. Southern Connecticut State University.
  • HPV Vaccine Effectiveness in New Haven County, Connecticut Women Aged 18-39, 2008-2012. Jennifer Berry (2014) MPH Thesis. Yale School of Public Health.
  • HPV Type Distribution in New Haven County, Connecticut Among Women with CIN2+ Diagnoses from 2008-2010. Chelsea Russ (2012) MPH Thesis. Yale School of Public Health.
  • The Prevalence of HPV Associated Disease in Women under Age 21: Who will be missed under the new cervical cancer screening guidelines? Amanda DeCew (2012) MPH Thesis. Yale School of Public Health.
  • HPV Vaccination Histories among High-Risk Women in New Haven County: Disparities and Barriers. Niti Mehta (2011) MPH Thesis. Yale School of Public Health.
  • Social Economic Characteristics and Cervical Abnormalities in Connecticut. James Santinelli (2010) MPH Thesis. Yale School of Public Health.

Connecticut HPV-IMPACT Newsletter

Recent Publications