Health and economic benefits of single-dose HPV vaccination in a Gavi-eligible country

Abstract

Background: Although guidelines for prophylactic human papillomavirus (HPV) vaccination recommend two doses for girls ages 9-14 years, several studies have demonstrated similar protection with one dose. Our objective was to evaluate the long-term health and economic impacts of routine one-dose HPV vaccination compared to (1) no vaccination and (2) two-dose HPV vaccination in a low-income country.

Methods: We used a three-tiered hybrid modeling approach that captured HPV transmission, cervical carcinogenesis, and population demographics to project long-term health and economic outcomes associated with one-dose HPV vaccination (assuming 80% efficacy against HPV-16/18 infections under three waning scenarios) and two-dose HPV vaccination (assuming 100% efficacy over the lifetime) in Uganda. Costs included the vaccine program (dosage and delivery) costs over a 10-year period and cervical cancer costs over the lifetimes of the current population of Ugandan women. Health outcomes included number of cervical cancer cases and disability-adjusted life years (DALYs). Incremental cost-effectiveness ratios (i.e., cost per DALY averted) were calculated and compared against the Ugandan per-capita gross domestic product.

Results: Routine one-dose HPV vaccination of 9-year-old girls required substantial upfront investment but was cost-saving compared to no vaccination when accounting for the cost-offsets from future cancers averted. Forty years after initiating routine vaccination and depending on assumptions of vaccine waning, one-dose HPV vaccination with equivalent coverage (70%) averted 15-16% of cervical cancer cases versus 21% with two-dose vaccination but required only half the upfront economic investment. Vaccination with two doses had an attractive cost-effectiveness profile except if one-dose vaccination enabled higher coverage (90% vs. 70%) and did not wane.

Conclusions: One-dose HPV vaccination resulted in cost-savings compared to no vaccination and could be cost-effective compared to two-dose vaccination if protection is longstanding and higher coverage can be achieved.

Keywords: Cervical cancer; Human papillomavirus; Vaccination.

Fig. 1

Overview of three-tiered model-based approach. Abbreviations. CC: cervical cancer, CIN: Cervical intraepithelial neoplasia, HPV: Human papillomavirus.

Fig. 2

Annual number of cervical cancer cases averted (Panel A) and total discounted economic costs (Panel B) associated with one-dose human papillomavirus (HPV) vaccination programs over time, assuming 70% vaccination coverage under alternative waning scenarios compared with no HPV vaccination and two-dose HPV vaccination. Percentage values (Panel A) represent the change in averted cancer cases in the population in years 2035 and 2055 following ten years of routine HPV vaccination, including indirect herd immunity benefits, compared with no HPV vaccination. For each calendar year, cases and costs are aggregated over multiple birth cohorts (i.e., the population of Ugandan women aged <50 years alive in 2017).

Fig. 3

Total discounted disability-adjusted life years (DALYs) (Panel A) and total discounted economic costs (Panel B) associated with one-dose human papillomavirus (HPV) vaccination at 70% vaccination coverage, cumulative over the lifetimes of women aged <50 years alive in year 2017. Vaccine program costs (red bars) reflect 10 birth cohorts of 9-year-old girls from years 2017–2026 (total 6,893,994 girls) at 70% vaccination coverage. Disease costs (blue bars) reflect disease offsets over the lifetimes of women aged <50 years alive in year 2017.