The global demand and potential public health impact of oral antiviral treatment stockpile for influenza pandemics

Stockpiling and rapid use of oral influenza antiviral drugs such as oseltamivir and baloxavir marboxil (BXM) can reduce the disease burden of a nascent influenza pandemic before vaccines are available. Current estimates for pandemic preparedness drug stockpile size vary widely depending on modeling assumptions and do not account for heterogeneities in healthcare-seeking behaviour or drug-specific transmission risk reduction. Here, we developed a novel transmission model that accounts for heterogeneous healthcare-seeking behaviour and recent estimates of transmission risk reduction by antivirals to estimate country-specific demand and impact of distributing oseltamivir and BXM in 186 countries. Due to its transmission reducing properties, BXM could maximally double the median percentage of mean pandemic deaths averted (37%-68%) relative to oseltamivir with ∼5%-10% with smaller stockpile size (7%-34% per-capita). Under limited drug availability, age-based rationing does not meaningfully lower total antiviral demand and drug priority should be given to treatment over post-exposure prophylaxis.