9HPV HEALTH AND ECONOMIC IMPACT OF HPV 16 AND 18 VACCINATION IN LATIN AMERICA AND THE CARIBBEAN

Wednesday, October 22, 2008
Columbus A-C (Hyatt Regency Penns Landing)
Sue J. Goldie, MD, MPH1, Mireia Diaz-Sanchis, MSc2, Steven G. Sweet, MBA1, Dagna Constenla, PhD, MPA3, Nelson Alvis, MD, PhD, MPH4, Jon Andrus, MD, MPH5 and Sun-Young Kim, PhD1, (1)Harvard School of Public Health, Boston, MA, (2)Catalan Institute of Oncology, Hospitalet de Llobregat, Spain, (3)Sabin Vaccine Institute, Denver, CO, (4)Universidad de Cartagena, Colombia, Colombia, (5)Pan American Health Organization, Washington, DC
Purpose: In Latin America and the Caribbean (LAC), screening has been unsuccessful in reducing cervical cancer mortality.  With the availability of a vaccine that prevents two common HPV types, cervical cancer prevention policy is being revisited. We assess the cost-effectiveness of HPV16,18 vaccination in 33 countries.
Methods: We have developed an individual-based stochastic model (all HPV types) and a dynamic transmission model (HPV 16,18), calibrated to epidemiologic data in several developing countries. Recognizing the data required for calibration is not universally available, we developed a companion excel-based model that relies on assumptions identified as reasonable based on comparative validation exercises. Using population-based and epidemiologic data for 33 LAC countries, we estimate averted cervical cancer cases and deaths, disability-adjusted years of life (DALYs) and incremental cost-effectiveness ratios (I$/DALY) associated with adolescent vaccination of girls. 
Results: Absolute reduction in lifetime cancer risk varied between countries, depending on incidence, proportion attributable to HPV16/18, and population age-structure; for example, with 70% coverage, reduction ranged from 40% in Chile to >50% in Argentina. Screening women > age 30, three to five times per lifetime, after vaccinating them as adolescents, is expected to provide an additional 25 to 30% reduction. Countries with the highest risk of cancer account for only 34% of deaths averted.. At I$25 per vaccinated girl ($5 per dose), for all 33 countries, the cost per DALY is less than I$400; at I$10 ($2.00 per dose) the vaccine is cost saving in 26 out of 33 countries. For all countries, ratios become less attractive as the cost of the vaccine increases. Vaccine price has an even greater effect on predicted affordability. For the 33 countries, vaccinating 5 consecutive birth cohorts at 70% coverage would be $360 million at $5.00 per dose, $811 million at $12.25 per dose, and $1.26 billion at $19.50 per dose.Conclusions: In LAC region, if effective delivery can achieve high coverage rates in young adolescent girls, vaccination against HPV16/18 will provide similar health value for resources invested as other new vaccines such as rotavirus.  If the cost per vaccinated girl is less than I$25 HPV16/18 vaccination would be very cost-effective in all 33 countries; for it to be affordable, costs may need to be lower.