Fig. 5

Threshold cost to pay for the first and second dose of vaccine by country income groups. The threshold cost is the maximum that could be paid for the first dose (compared to no vaccination) and second dose (compared to one dose only) for the incremental cost-effectiveness ratio to remain below the cost-effectiveness threshold. Two cost-effectiveness thresholds are presented: a lower threshold as suggested by Jit (2020) [53] in (A–D) and country gross domestic product (GDP) per capita (in 2017 USD) in (E–H). The lower cost-effectiveness threshold presented in A–D is 30–40% and 60–65% of GDP per capita in low-income and middle- to high-income countries, respectively. Cost and health outcomes were discounted at 3% and 0%, respectively