Stable vaccines with long shelf lives and reduced dependency on the cold chain are ideal for stockpiling and rapid deployment during public emergencies, including pandemics. Spray-drying is a low-cost process that has potential to produce vaccines stable at a wide range of temperatures. This publication describes development of a recombinant H1N1 influenza hemagglutinin vaccine candidate (HAC1) and the scale-up work performed to spray-dry the formulation at the pilot scale. The pilot-scale process was used to reproducibly manufacture three batches of the selected formulation with yields >90%.