Viral and bacterial respiratory infections remain the number one cause of infectious disease-related deaths around the world. In the past, vaccines were often created by repeatedly passing laboratory cultures to develop attenuated strains or simply by inactivating live cultures of pathogens. A variety of new and innovative technologies are being applied to develop vaccines against the more elusive pathogens. A variety of protein conjugates have been used to greatly enhance the immunogenicity of Haemophilus influenzae type B vaccine, and are now being employed for new pneumococcal and meningococcal vaccines. Live attenuated vaccine strains of respiratory syncytial virus and influenza, which induce protective immunity through localized replication in the nasopharynx, may soon be available for routine use. Future innovations may include genetic vaccines that introduce DNA into host cells to produce specific protective antigens, along with a desired cytokine response to induce a protective immune response.