A new peer-reviewed article uses a static Markov cohort model to compare single-dose and two-dose HPV vaccination schedules in a composite low- and middle-income country setting combining parameters from Kenya and India. The model follows 100,000 girls from age 9 across a lifetime horizon, estimating costs, cases and deaths averted, and DALYs averted under each schedule relative to no vaccination, while also exploring how assumptions around vaccine protection duration influence these results.
Key findings
- Both single-dose and two-dose HPV vaccination were cost-saving and more effective than no vaccination, remaining cost-effective across probabilistic sensitivity analyses.
- Under the base-case assumption of 20-year single-dose protection, single-dose vaccination averted more DALYs and saved more costs than the two-dose schedule (assumed lifelong protection), mainly due to higher effective coverage after accounting for second-dose dropout.
- Scenario analyses showed that the cost-effectiveness advantage of single-dose over two-dose vaccination widened as second-dose dropout rates increased.
- The relative cost-effectiveness of the two strategies was highly sensitive to assumptions around the duration of protection following a single dose. The authors show that the apparent DALY advantage of single-dose vaccination versus two-dose vaccination narrows or disappears if single-dose protection is shorter or longer than the 20-year base-case assumption.
- Across all scenarios examined, the two-dose strategy prevented more invasive cervical cancer cases and deaths than the single-dose strategy, highlighting that conclusions differ depending on whether decision-makers prioritise DALYs averted or absolute cases and deaths prevented.
