Health and economic effects of introducing single-dose human papillomavirus vaccination in India

BackgroundCervical cancer is a major public health problem in India, where access to prevention programmes is low. The World Health Organization-Strategic Advisory Group of Experts recently updated their recommendation for human papillomavirus (HPV) vaccination to include a single-dose option in addition to the two-dose option, which could make HPV vaccination programmes easier to implement and more affordable. MethodsWe combined projections from a type-specific HPV transmission model and a cancer progression model to assess the health and economic effects of HPV vaccination at national and state-level in India. The models used national and state-specific Indian demographic, epidemiological and cost data, and single-dose vaccine efficacy and immunogenicity data from the IARC India vaccine trial with 10-year follow-up. We compared single- and two-dose HPV vaccination for a range of plausible scenarios regarding single-dose vaccine protection, coverage and catch-up. ResultsUnder the base-case scenario of life-long protection of single-dose vaccination in 10-year-old girls with 90% coverage, the incremental cost-effectiveness ratio (ICER) of nationwide vaccination relative to no vaccination was $405 per DALY averted and lay below an opportunity-cost based threshold of 30% Indian GDP per capita in each state (state-specific ICER range: $67 to $593 per DALY averted). The ICER of two-dose vaccination versus no vaccination and versus single-dose vaccination was $1403 and minimum $2279 per DALY averted, respectively. ConclusionsNationwide introduction of single-dose HPV vaccination in India is highly likely to be cost-effective whereas extending the number of doses from one to two would have a less favourable profile. FundingBill & Melinda Gates Foundation. What is already known in this topicIn 2020, the World Health Organization (WHO) launched a global call for elimination of cervical cancer as a public health problem, of which HPV vaccination is a key pillar. However, access to HPV vaccination in India is still very low. In April 2022, the WHO Strategic Advisory Group of Experts (SAGE) issued a recommendation for countries to update their dosing schedules to include a single-dose option. Single-dose HPV vaccination is likely to be more affordable and would greatly facilitate the implementation of HPV vaccination. The key questions for India are whether, with a realistic cost-effectiveness threshold (30% GDP per capita), single-dose HPV vaccination would be a cost-effective intervention; and whether two-dose vaccination could still be affordable and worthwhile compared to a single-dose schedule, given the uncertainty in its initial efficacy and long-term protection. What this study addsWe used state-specific cancer incidence and locally collected cost data and built plausible vaccination efficacy scenarios based on the IARC India trial to inform the cost-effectiveness estimates. Single-dose vaccination in India would be cost-effective under a cost-effectiveness threshold of 30% of the Indian GDP per capita and the annual budget impact would be less than 10% of the cost of the current Indian universal childhood vaccination programme. Even though there was substantial heterogeneity, we confirmed that single-dose vaccination would be cost-effective across all Indian states. Catch-up single-dose vaccination to age 15 or 20 is a cost-effective strategy. However, the decision to implement catch-up will depend on the willingness of the health authorities to support a higher initial investment. We found two-dose vaccination to have a less favourable cost-effectiveness profile. How this study might affect research practice and policySingle-dose vaccination achieved a better balance between health benefits and financial burden than two-dose vaccination, even after taking into account uncertainty in the level of protection provided by single-dose HPV vaccination. Our results could be used by Indian health authorities at the national and state-level to inform their decision and planning of the implementation of HPV vaccination in India and could convey several lessons for other low and middle income countries.