OBJECTIVES: To assess the public health and economic impact of adding males to the existing 9-10-year-old female-only vaccination (FOV) with two-dose schedule of quadrivalent HPV vaccine (4vHPV) from the El Salvador public health system perspective.

METHODS: A published HPV transmission dynamic model was calibrated to compare gender-neutral vaccination (GNV) strategy at vaccination coverage rate (VCR) of 65% (scenario A) and 80% (scenario B) against 9-10-year-old FOV at 65% VCR. The model assumed two-dose schedule over a 100-year time-horizon, lifelong immunity, herd immunity, ongoing cytology screening, and a discount rate of 3%. The outcomes were HPV 6/11/16/18-related diseases: cervical intraepithelial neoplasia (CIN), cervical cancer (CC), non-cervical cancers (vagina/vulva/anus/head and neck/penis), genital warts (GW), and recurrent respiratory papillomatosis (RRP). The incremental cost-effectiveness ratio was estimated as the ratio of incremental costs to incremental quality-adjusted life years.

RESULTS: Both GNV scenarios were projected to avert additional cases in all HPV 6/11/16/18-related-diseases compared to FOV. Highest cumulative reductions were seen in scenario B over 100 years: 9.6% for CC; 19.7% for CIN2/3; 20.1% for CIN1; 12.6% and 8.3% for male and female H&N cancer; 19.5% and 12.1% for male and female anal cancer, respectively; 19.1% for penile cancer; and 42.4 and 37.5% for male and female RRP, respectively; 35% (502,621 cases) and 25.8% (352,543 cases) for male and female GW, respectively. Both GNV scenarios were estimated to provide faster and greater reductions in HPV 6/11/16/18-related diseases relative to FOV. The greatest projected reductions in medical costs were due to HPV-6/11-related diseases (>96%), driven by GW. In scenarios A and B, GNV was dominant over FOV with net cost savings of 18.4-and 32 million, respectively.

CONCLUSIONS: Under the model assumptions, GNV was a cost-saving strategy in El Salvador, providing faster and greater reductions in HPV 6/11/16/18-related diseases in both women and men relative to FOV.