A new coronavirus vaccine approach works by attaching many spike protein receptor-binding domains (RBDs) to an engineered protein-based nanoparticle. In mice, the vaccine induced a cross-reactive antibody response capable of neutralizing many different coronavirus strains. The findings raise the exciting possibility that this new vaccine technology could provide protection against many coronavirus strains with a single shot. Of course, far more study is needed to explore how well such vaccines work to protect animals against infection, and whether they will prove to be safe and effective in people. There will also be significant challenges in scaling up manufacturing. Our goal is not to replace the mRNA COVID-19 vaccines that scientists developed at such a remarkable pace over the last year, but to provide much-needed vaccine strategies and tools to respond swiftly to the emerging coronavirus strains of the future.