Examples of class I adjuvants (delivery systems)
| Mode of action(s) | Types of response | Pros | Cons | |
|---|---|---|---|---|
| IFA and Montanide formulations | Depot | Ab, Th1, Th2 | Widely used for vaccines when antibody production is desired [123]. | May not suitable for therapeutic vaccine when cellular response is desired as extended depot will attract CTL to vaccine sites [10]. |
| Aluminum | Depot, inflammasome activation | Ab, Th2 | Safety characters are well defined as it is the most widely used adjuvant [124]. | Needs to be combined with other adjuvants to induce CTL response in therapeutic vaccines. |
| Micro/nano particles | Varies, depending on particlenature: increase Ag half-life (via encapsulation, sustained release) delivery Ag to target cells/organs, cellular and Inflammation induction (see text for detail) | Not well defined but size of articles may contribute to types of response: size of 40–50 nm induces stronger T cell response than 20nm or 2000 nm particles 4. | Reduce Ag dose, cellular and biological characters are well defined, versatile to be combined with other adjuvants [121]. | Rapid clearance in blood and accumulation in filtering organs such as liver and spleen [24].Need to be combined with immunopotentiators. |