Communicable respiratory infections are the cause of a significant number of infectious diseases. The introduction of vaccinations has greatly improved this situation. Moreover, adjuvants have allowed for vaccines to be more effective with fewer adverse side effects. However, there is still space for improvement because while the more common injected formulations induce a systematic immunity, they do not confer the mucosal immunity needed for more thorough prevention of the spread of respiratory disease. Intranasal formulations provide systemic and mucosal immune protection, but they have the potential for more serious side effects and a less robust immune response. This review looks at seven different adjuvants-chitosan, starch, alginate, gellan, β-glucan, emulsan and hyaluronic acid-and their prospective ability to improve intranasal vaccines as adjuvants and antigen delivery systems.
Keywords: immunomodulation; mucosal administration; nanovaccines; polymeric vaccines; respiratory infections.