Public health impact and cost-effectiveness of implementing gender-neutral immunization with the nonavalent human papillomavirus vaccine in South Korea

This study assessed the impact and cost-effectiveness of gender-neutral immunization with the nonavalent human papillomavirus (HPV) vaccine in South Korea. An established dynamic transmission model of HPV epidemiology was adapted to the South Korean population. Vaccinating both girls and boys with the nonavalent HPV vaccine was compared to the currently administered program of vaccinating girls only with the quadrivalent vaccine. Compared to vaccination of girls only with the quadrivalent HPV vaccine, gender-neutral vaccination with the nonavalent HPV vaccine was projected to prevent 1,282,415 cases of cervical intraepithelial neoplasia grade 1 (CIN1), 918,384 cases of CIN2/3, 36,248 cases of cervical cancer, and 9,313 cervical cancer deaths in females over 100 years. Gender-neutral vaccination was projected to reduce HPV-related vaginal, vulvar, anal, and head & neck cancers in females by 4.8-8.2%, in addition to reductions of 14.6% and 15.8% in genital warts and recurrent respiratory papillomatosis, respectively. In males, gender-neutral vaccination was projected to prevent 666,182 cases of genital warts, 7,422 cases of RRP, 995 cases of anal cancer, 2,441 cases of head & neck cancer, and 122 cases of penile cancer. The incremental cost-effectiveness ratio (ICER) was ₩38.9 million per quality-adjusted life year (QALY), which is below the accepted cost-effectiveness threshold in South Korea. These findings suggest that gender-neutral vaccination with the nonavalent HPV vaccine would reduce the public health burden of HPV disease in both females and males in South Korea and would be cost-effective under base case assumptions about vaccine price and coverage of boys.