With the ongoing COVID-19 pandemic, the need for general-purpose antiviral materials has never been more relevant. Metallic nanoparticles, and silver nanoparticles (AgNPs) in particular, have received considerable attention through efforts to meet this need. But what is it that makes AgNPs effective against viruses? How has this effectiveness been measured and quantified? And how can AgNPs be incorporated into products and treatments effectively? Answers to these questions provided by the scientific community are invaluable for separating the facts from the hype.