Modeling the impact of the difference in cross-protection data between a human papillomavirus (HPV)-16/18 AS04-adjuvanted vaccine and a human papillomavirus (HPV)-6/11/16/18 vaccine in Canada

• Published in: BMC public health 2012-10, Vol.12 (1), p.872-872, Article 872
• Main Authors: Kohli, Michele, Lawrence, Donna, Haig, Jennifer, Anonychuk, Andrea, Demarteau, Nadia
• Format: Article
• Language: English
• Subjects: Adjuvants, Immunologic - economics; Age groups; Canada; Cervical cancer; Child; Condylomata Acuminata - economics; Condylomata Acuminata - prevention & control; Condylomata Acuminata - virology; Cost-Benefit Analysis; Cost-effectiveness; Cross Protection; Female; Follow-Up Studies; Health Care Costs - statistics & numerical data; Human papillomavirus; Human papillomavirus 11 - immunology; Human papillomavirus 16 - immunology; Human papillomavirus 18 - immunology; Human papillomavirus 6 - immunology; Humans; Immunization; Infections; Markov Chains; Markov model; Mass Vaccination - economics; Mass Vaccination - methods; Models, Economic; Papillomavirus Infections - economics; Papillomavirus Infections - prevention & control; Papillomavirus Infections - virology; Papillomavirus Vaccines - economics; Provinces; Quality-Adjusted Life Years; Uterine Cervical Neoplasms - economics; Uterine Cervical Neoplasms - prevention & control; Uterine Cervical Neoplasms - virology; Vaccine; Vaccines; Womens health
• ISSN: 1471-2458; 1471-2458
• DOI: 10.1186/1471-2458-12-872

In Canada, two vaccines that have demonstrated high efficacy against infection with human papillomavirus (HPV) types -16 and -18 are available. The HPV-6/11/16/18 vaccine provides protection against genital warts (GW) while the HPV-16/18 vaccine may provide better protection against other oncogenic HPV types. In this analysis, the estimated clinical and economic benefit of each of these vaccines was compared in the Canadian setting. A Markov model of the natural history of HPV infection among women, cervical cancer (CC) and GW was used to estimate the impact of vaccinating a cohort of 100,000 12-year-old females on lifetime outcomes and healthcare system costs (no indirect benefit in males included). A budget impact model was used to estimate the impact of each vaccine by province. In the base case, vaccination with the HPV-16/18 vaccine was predicted to prevent 48 additional CC cases, and 16 additional CC deaths, while vaccination with the HPV-6/11/16/18 vaccine was predicted to prevent 6,933 additional GW cases. Vaccination with the HPV-16/18 vaccine was estimated to save 1 additional discounted quality adjusted life year (QALY) at an overall lower lifetime cost to the healthcare system compared to the HPV-6/11/16/18 vaccine (assuming vaccine price parity). In sensitivity analyses, the HPV-6/11/16/18 vaccine was associated with greater QALYs saved when the cross-protection efficacy of the HPV-16/18 vaccine was reduced, or the burden of GW due to HPV-6/11 was increased. In most scenarios with price parity, the lifetime healthcare cost of the strategy with the HPV-16/18 vaccine was predicted to be lower than the HPV-6/11/16/18 vaccine. In the probabilistic sensitivity analyses, the HPV-16/18 vaccine provided more QALY benefit than the HPV-6/11/16/18 vaccine in 49.2% of scenarios, with lower relative lifetime costs in 83.5% of scenarios. Overall, the predicted lifetime healthcare costs and QALYs saved by implementing each of the vaccines are similar. Vaccination with the HPV-16/18 vaccine is expected to be associated with reduced CC disease morbidity and mortality compared to vaccination with the HPV-6/11/16/18 vaccine. Differences in these outcomes depend on the extent of cervical disease prevented by cross-protection and the burden of GW caused by HPV-6/11.