The Wistar Institute published preclinical data showing a single-immunization vaccine candidate elicited neutralizing antibodies against HIV in nonhuman primates. The Nature Immunology study reports that a single-shot regimen produced a measurable neutralizing response, challenging conventional assumptions that multiple boosts are required for broadly neutralizing activity. If the signal translates to humans, the result could materially alter HIV vaccine strategies by simplifying dosing schedules and reducing logistical barriers for high-burden settings. The Wistar report will prompt rapid follow-up studies to assess durability, breadth, and translational potential.