Health economic analysis of antiviral drugs in the global polio eradication endgame

BACKGROUND: Pollio antiviral drugs (PAVDs) may provide a critical tool in the eradication endgame by stopping poliovirus infections in immunodeficient individuals who may not clear the virus without therapeutic intervention. Although prolonged/chronic poliovirus excreters are rare, they represent a source of poliovirus reintroduction into general population. Prior studies that assumed successful cessation of all oral poliovirus vaccine (OPV) use estimated the potential upper bound of the incremental net benefits (INBs) of resource investments in research and development of PAVDs. However, delays in polio eradication, OPV cessation, and the development of PAVDs necessitate an updated economic analysis to reevaluate the costs and benefits of further investments in PAVDs. METHODS: Using a global integrated model of polio transmission, immunity, vaccine dynamics, risks, and economics, we explore the risks of reintroduction of polio transmission due to immunodeficiency-related vaccine derived poliovirus (iVDPV) excreters and reevaluate the upper bound of the INBs of PAVDs. RESULTS: Under the current conditions, for which the use of OPV will likely continue for the foreseeable future, even with successful eradication of type 1 WPV by the end of 2023 and continued use of Sabin OPV for outbreak response, we estimate upper bound INB of 60 million US$2019. With >100 million US$2019 already invested in PAVD development and with the introduction of novel OPVs that are less likely to revert to neurovirulence, our analysis suggests the expected INBs of PAVDs would not offset their costs. CONCLUSIONS: While PAVDs could play an important role in the polio endgame, their expected economic benefits drop with ongoing OPV use and poliovirus transmissions. However, stakeholders may pursue development of PAVDs as a desired product regardless of their economic benefits.