HEALTH AND ECONOMIC IMPACT OF HPV 16 AND 18 VACCINATION IN GAVI-ELIGIBLE COUNTRIES

Purpose: The risk of dying from cervical cancer is disproportionately borne by women in developing countries. Two new vaccines prevent HPV16/8 infection, responsible for approximately 70% of cervical cancer, in girls not previously infected. The Global Alliance for Vaccines and Immunization (GAVI) provides technical assistance and financial support for immunization in the poorest countries. To provide qualitative insight for GAVI deliberations, we assess the cost-effectiveness of HPV16,18 vaccination in 72 GAVI-eligible countries.
Methods: We have developed models of cervical carcinogenesis that include a dynamic transmission model (HPV 16,18) and an individual-based stochastic model (all HPV types) calibrated to epidemiologic data in 10 developing countries. Recognizing the full range of data required for calibration is not available for most poor countries, we developed a companion model that relies on simplifying assumptions identified as reasonable using our more complex empirically-calibrated models. Using population-based and epidemiologic data for 72 GAVI-eligible countries we estimate averted cervical cancer cases and deaths, disability-adjusted years of life averted (DALYs) and incremental cost-effectiveness ratios (I$/DALY) associated with HPV16/18 vaccination of young adolescent girls. 
Results: With 70% coverage, mean reduction in lifetime cancer risk is <40% in some countries (e.g.,Nigeria, Ghana) and >50% in others (e.g., India, Uganda, Kenya).  At I$10 per vaccinated girl (~$2.00 per dose, three doses, plus wastage, administration, program support) vaccination was cost-effective in all countries using a per capita GDP threshold; for 49 of 72 countries, the cost per DALY averted was < I$100; for 59 countries, it was < I$200. Taking into account country-specific assumptions (per capita GNI, DPT3 coverage, percentage of girls enrolled in 5th grade), percent coverage achieved in the first year, and years to maximum coverage, a ten-year modeled scenario prevented the future deaths of ~2 million women vaccinated as adolescents. Despite favorable cost-effectiveness, assessment of financial costs raised concerns about affordability; as the cost-per-vaccinated-girl was increased from $2 to $5 per dose, the financial costs for the ten-year scenario increased from ~US$952 million to US$2.35 billion.
Conclusions: Provided high coverage of young adolescent girls is feasible, and vaccine costs are lowered, HPV16/18 vaccination could be cost-effective even in the poorest countries, and provide comparable value for resources compared to other new vaccines such as rotavirus.