A Cost-effectiveness Study of the Quadrivalent HPV6/11/16/18 Vaccination in a Two-dose Scheme in Girls of 9-11 Years Old Compared to Bivalent HPV 16/18 Vaccination in Ecuador and Challenges for Public Health and Screening

Aims: Assess the incremental cost-effectiveness of the quadrivalent HPV6/11/16/18 vaccination as administered in a two-dose scheme to girls between 9 and 11 years old, as compared to the bivalent HPV 16/18 vaccination administered in Ecuador, and to estimate the cost-saving of preventing GW while preventing cervical cancer with both vaccines.

Study Design: We used a previously developed transmission dynamic mathematical model to evaluate the impact of routine vaccination of 9-11 year-old females. The model assumed coverage of 90% for two doses of HPV6/11/16/18 vaccine at international price rates versus HPV16/18 vaccine and costs for genital warts treatment. Other simulation parameters include: country socio- demographic variables, sexual behavior and screening parameters among Ecuadorian girls.

Results: Over a 100-year period, HPV6/11/16/18 vaccination would result in reductions of HPV 6/11-related disease incidence at the population level as follows: genital warts in females (81.3%), genital warts in males (78.9%) and HPV6/11-related CIN1 (79.7%). These results would translate into a reduction of HPV 6/11-related disease cost of between 52% to 56% for genital warts among females, genital warts among males, and HPV6/11-related CIN1. Under the model assumptions, the estimated net cost of vaccination with the HPV6/11/16/18 vaccine from a public health perspective would be close to -USD$256 million. Adjusted to the net present value, this cost-saving represents USD$180,735,849.09 with a present value interest factor of 0.9512.

Conclusions: In Ecuador, routine vaccination of 9-11 year old females with a quadrivalent HPV6/11/16/18 vaccine is cost-saving compared to a bivalent HPV 16/18 vaccine, which suggests a significant public health and economic impact.