Antivirals for seasonal influenza in the US: modeling direct and indirect effects with variable uptake
- 1Centers for Disease Control and Prevention
Abstract
Influenza antivirals can directly benefit treated individuals by reducing the risk of some influenza-associated complications when initiated soon after symptom onset. Antivirals may also reduce onward transmission, and previous modeling studies including such indirect effects have estimated large population-level reductions in influenza-associated disease outcomes. However, these studies often assume an optimistic number of people initiate, and adhere to, prompt treatment. Using a compartmental framework, we modeled population-level reductions in influenza-associated hospitalizations given potential direct and indirect effects of influenza antivirals in the United States. From reported patterns of care-seeking, antiviral prescribing, and treatment adherence, we estimated 1.1-9.7% of symptomatic individuals initiate and adhere to prompt antiviral treatment. We estimated small direct effects of antivirals in example seasons, with 0.9% of hospitalizations prevented when antivirals reduced hospitalization risk by 20%. Assuming antivirals had direct and indirect effects generated slightly larger impacts. For example, up to 3.8% of hospitalizations were prevented when antivirals reduced hospitalization risk and onward transmission by 20%. More substantial impacts (for example, preventing >20% of hospitalizations) were only achieved by increasing initiation and adherence to prompt treatment beyond typically observed levels. Therefore, prompt treatment initiation and adherence are critical factors shaping potential population-level impacts of influenza antivirals.
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BibTeX
@misc{morris2026antivirals,
title = {{Antivirals for seasonal influenza in the US: modeling direct and indirect effects with variable uptake}},
author = {S. E. Morris and S. G. Dean and L. Y. H. Chan and S. Garg and T. M. Uyeki and R. K. Borchering and M. Biggerstaff and A. M. Mellis},
howpublished = {medRxiv},
year = {2026},
month = sep,
doi = {10.64898/2026.09.10.26362674},
url = {https://www.medrxiv.org/content/10.64898/2026.09.10.26362674v1},
note = {CC0},
}
RIS
TY - UNPB
TI - Antivirals for seasonal influenza in the US: modeling direct and indirect effects with variable uptake
AU - S. E. Morris
AU - S. G. Dean
AU - L. Y. H. Chan
AU - S. Garg
AU - T. M. Uyeki
AU - R. K. Borchering
AU - M. Biggerstaff
AU - A. M. Mellis
PY - 2026
DA - 2026/09/10
PB - medRxiv
DO - 10.64898/2026.09.10.26362674
UR - https://www.medrxiv.org/content/10.64898/2026.09.10.26362674v1
AB - Influenza antivirals can directly benefit treated individuals by reducing the risk of some influenza-associated complications when initiated soon after symptom onset. Antivirals may also reduce onward transmission, and previous modeling studies including such indirect effects have estimated large population-level reductions in influenza-associated disease outcomes. However, these studies often assume an optimistic number of people initiate, and adhere to, prompt treatment. Using a compartmental framework, we modeled population-level reductions in influenza-associated hospitalizations given potential direct and indirect effects of influenza antivirals in the United States. From reported patterns of care-seeking, antiviral prescribing, and treatment adherence, we estimated 1.1-9.7% of symptomatic individuals initiate and adhere to prompt antiviral treatment. We estimated small direct effects of antivirals in example seasons, with 0.9% of hospitalizations prevented when antivirals reduced hospitalization risk by 20%. Assuming antivirals had direct and indirect effects generated slightly larger impacts. For example, up to 3.8% of hospitalizations were prevented when antivirals reduced hospitalization risk and onward transmission by 20%. More substantial impacts (for example, preventing >20% of hospitalizations) were only achieved by increasing initiation and adherence to prompt treatment beyond typically observed levels. Therefore, prompt treatment initiation and adherence are critical factors shaping potential population-level impacts of influenza antivirals.
ER -