Microarray patch vaccines for typhoid conjugate vaccines: A global cost-effectiveness analysis

A novel typhoid conjugate vaccine (TCV) presentation, the microarray patch (MAP), is in early-stage development and could potentially help to increase coverage in hard-to-reach populations beyond what is being achieved with the current TCV in a vial presentation administered with a needle and syringe (TCV-N&S). However, TCVMAPs may come at a higher price per dose than TCV-N&S. Our analysis evaluated the potential cost-effectiveness of TCV-MAPs alongside TCV-N&S compared to TCV-N&S alone. A global extended cost-effectiveness analysis, taking a health care perspective, was conducted for 133 low-to upper-middle-income countries for a time horizon of 20 years (2033-2052). Health outcomes were expressed in disability-adjusted life years (DALYs) and costs in 2021 US dollars, both discounted at 3 %. We assumed TCVMAP would cost 1.33 to 3 times the price of the TCV-N&S vaccine. We calculated incremental costeffectiveness ratios and evaluated them against various cost-effectiveness thresholds. For five selected countries, we conducted an additional subnational analysis to understand the potential value of a district-specific TCV-MAP implementation instead of a national rollout. Across the 133 low-to upper-middle-income countries, national rollout of TCV-MAPs could avert an additional 5.2 million cases, 47,000 deaths, and 2.4 million DALYs compared to TCV-N&S only, at an additional cost of US $3.5 billion over 20 years. The largest proportion of the averted burden would be in the sub-Saharan African region. TCV-MAPs could be cost-effective in 33 % of the countries but in 78 % of sub-Saharan African countries. A subnational implementation could benefit some countries for which a national implementation may not be cost-effective, averting 2-15 % of cases for less than 1-3 % of the additional cost as compared to a national rollout. MAP price was a key driver of the results. Regional or subnational implementation, coupled with a lower price point, could significantly improve the TCV-MAP value proposition.