Cody Palmer

A cost-effectiveness analysis of adult human papillomavirus vaccination strategies in Italy

Vaccination can reduce the public health and economic burden of human papillomavirus (HPV)-associated diseases. In 2023, the Italian national immunization program (NIP) was updated to include HPV vaccination of females ≤26 and males ≤18 years. However, the cost-effectiveness of this update along with proposals to include additional cohorts is unknown. This study evaluates the cost-effectiveness of different HPV vaccination strategies in Italy over a 100-year period, using a published dynamic transmission model with Italy-specific input data. We modeled vaccination of the primary cohort (11 years of age) for 100 years, alone and supplemented with vaccination of additional cohorts for 5-100 years. We found that vaccination of the primary adolescent cohort resulted in substantial, sustained decreases in the incidence and mortality rates of all HPV-related cancers, but smaller, transient decreases in genital warts and recurrent respiratory papillomatosis. Adding supplementary vaccination of additional cohorts for 5-10 years had minor additional public health benefits, while continuing any of the modeled supplementary vaccination strategies for 100 years resulted in more substantial incremental benefits. For example, implementing the 2023-2025 NIP strategy for 100 years averted an additional 21,495 cases of cervical cancer compared to vaccination of the primary cohort alone. All supplementary vaccination strategies that were continued for 10 or 100 years were cost-effective compared to vaccination of the primary cohort alone at a willingness-to-pay threshold of €40,000 per quality-adjusted life year (QALY) gained. The benefits deriving from vaccinating additional cohorts should be considered when developing and updating NIPs.

Public health impact and cost-effectiveness of catch-up 9-valent HPV vaccination of individuals through age 45 years in the United States

The Advisory Committee on Immunization Practices (ACIP) recommended catch-up 9-valent Human Papillomavirus (HPV) vaccination through age 26 years, and shared clinical decision-making for adults aged 27-45 years, compared with catch-up through age 26 years and 21 years for females and males, respectively (status quo; pre-June-2019 recommendations). This study assessed the public health impact and cost-effectiveness of expanded catch-up vaccination through age 45 years (expanded catch-up) compared with status quo. We used an HPV dynamic transmission infection and disease model to assess disease outcomes and incremental cost-effectiveness ratio (ICER) of expanded catch-up compared with status quo. Costs (2018 USD), calculated from a healthcare sector perspective, and quality-adjusted life years (QALY) were discounted at 3% annually. Historical vaccination coverage was estimated using NIS-TEEN survey data (NHANES data for sensitivity analysis). Alternative scenario analyses included restricting upper age of expanded catch-up through 26 years (June-2019 ACIP recommendation), 29 years, and further 5-year increments. Our results show expanded catch-up vaccination would prevent additional 37,856 cancers, 314,468 cervical intraepithelial neoplasia-2/3s, 1,743,461 genital warts, and 10,698 deaths compared with status quo over 100 years at cost of $141,000/QALY. With NHANES coverage, the ICER was $96,000/QALY. The June-2019 ACIP recommendation also provided public health benefits with an ICER of $117,000/QALY, compared with status quo. The ICER for expanded vaccination through age 34 years was $107,000/QALY. Expanding catch-up vaccination program through age 45 years-old in the US is expected to provide public health benefits, and cost-effectiveness improves with expanding catch-up through age 34.

Public health impact and cost effectiveness of routine and catch-up vaccination of girls and women with a nine-valent HPV vaccine in Japan: a model-based study

Abstract Background Combined with cancer screening programs, vaccination against human papillomavirus (HPV) can significantly reduce the high health and economic burden of HPV-related disease in Japan. The objective of this study was to assess the health impact and cost effectiveness of routine and catch-up vaccination of girls and women aged 11–26 years with a 4-valent (4vHPV) or 9-valent HPV (9vHPV) vaccine in Japan compared with no vaccination. Methods We used a mathematical model adapted to the population and healthcare settings in Japan. We compared no vaccination and routine vaccination of 12–16-year old girls with 1) 4vHPV vaccine, 2) 9vHPV vaccine, and 3) 9vHPV vaccine in addition to a temporary catch-up vaccination of 17–26 years old girls and women with 9vHPV. We estimated the expected number of disease cases and deaths, discounted (at 2% per year) future costs (in 2020 ¥) and discounted quality-adjusted life years (QALY), and incremental cost effectiveness ratios (ICER) of each strategy over a time horizon of 100 years. To test the robustness of the conclusions, we conducted scenario and sensitivity analyses. Results Over 100 years, compared with no vaccination, 9vHPV vaccination was projected to reduce the incidence of 9vHPV-related cervical cancer by 86% (from 15.24 new cases per 100,000 women in 2021 to 2.02 in 2121). A greater number of cervical cancer cases (484,248) and cancer-related deaths (50,102) were avoided through the described catch-up vaccination program. Routine HPV vaccination with 4vHPV or 9vHPV vaccine prevented 5,521,000 cases of anogenital warts among women and men. Around 23,520 and 21,400 diagnosed non-cervical cancers are prevented by catch-up vaccination among women and men, respectively. Compared with no vaccination, the ICER of 4vHPV vaccination was ¥975,364/QALY. Compared to 4vHPV, 9vHPV + Catch-up had an ICER of ¥1,534,493/QALY. Conclusions A vaccination program with a 9-valent vaccine targeting 12 to 16 year-old girls together with a temporary catchup program will avert significant numbers of cases of HPV-related diseases among both men and women. Furthermore, such a program was the most cost effective among the vaccination strategies we considered, with an ICER well below a threshold of ¥5000,000/QALY.