The Phase III randomized controlled trial published in the New England Journal of Medicine demonstrates ensitrelvir reduced symptomatic COVID-19 in household contacts by 67% (risk ratio 0.33) when started within 72 hours of index case symptoms, with a modified intention-to-treat population of 2,041 participants across five countries. This double-blind, placebo-controlled study from June 2023 to September 2024 stands out for its rigorous design and low adverse event rates comparable to placebo, though manufacturer Shionogi's involvement introduces potential conflicts of interest that warrant scrutiny of long-term data. Original coverage overlooked how this positions ensitrelvir as a practical bridge in the Omicron era, where household secondary attack rates reach 32-48% and nonpharmaceutical interventions falter. Unlike vaccines focused on primary prevention, post-exposure antivirals address immediate transmission gaps, especially in congregate living or among those with risk factors showing 2.4% versus 9.9% infection rates. Related research in JAMA Network Open on Paxlovid post-exposure prophylaxis revealed weaker effects, underscoring ensitrelvir's unique advantage. Patterns from prior antiviral rollouts suggest underemphasis stems from vaccine-centric policies, missing opportunities to integrate both tools for sustained control.