OBJECTIVES

: Human papillomavirus (HPV) is a known cause of a variety of malignant diseases as well as recurrent respiratory papillomatosis (RRP) and genital warts in both genders. In Flanders, northern region of Belgium, HPV vaccination of 12-13 year olds with a nine-valent (9v) vaccine has been established for girls since 2018 and for boys since 2019. The aim of this study is to model expected public health impact and cost-effectiveness of 9vHPV gender-neutral vaccination in Flanders.

METHODS

: A published HPV-type transmission dynamic model accounting for herd protection has been adapted and calibrated for Flanders. The model considered the occurrence of genital warts, cervical intraepithelial neoplasia, cervical, vaginal, vulvar and anal cancers, and RRP, penile and H&N cancers. A 2-dose schedule and a vaccination coverage rate (VCR) of 90% were used in the base case analysis for both cohorts. Deterministic sensitivity analyses were performed on key parameters (incidence of genital warts and HPV related cancers, VCR, duration of protection and vaccine cost).

RESULTS

: The addition of boys to the vaccination cohort is projected to result in a reduction of 2346, 490 and 429 cases and 1175, 67 and 81 deaths of H&N, penile and anal cancers, respectively, in males over a 100-years period. Notably, vaccination of boys with 9vHPV resulted in an additional reduction of 83826 genital warts, 6162 cervical intraepithelial neoplasia cases, and 436 cases and 127 deaths by cervical cancer compared to the girls-only vaccination strategy over a period of 100 years. Moreover, the GNV strategy is projected to reduce cumulative HPV-related disease costs by 6% over 100 years. The base-case incremental cost-effectiveness ratio (ICER) of the 9vHPV GNV is €8062/QALY.

CONCLUSIONS

: This study demonstrates that modeled prediction of addition of boys to the HPV vaccination program in Flanders will generate additional benefits in terms of public health impact.