The U.S. Biomedical Advanced Research and Development Authority (BARDA) launched a $100 million prize competition to accelerate small‑molecule antivirals targeting Togaviridae and Flaviviridae. The agency opened the first stage of the program this week, inviting proposals that could fast‑track broad‑spectrum therapeutics against families that include dengue, chikungunya and Zika (Togaviridae) and flaviviruses such as West Nile and yellow fever. BARDA’s prize model aims to de‑risk early medicinal chemistry and candidate optimization outside traditional grant channels and stimulate industry competition for antivirals suitable for pandemic preparedness.