Complement-derived molecular adjuvants

Principally because of this latter reason, these pharmacologically active components of complement are attractive as molecular adjuvants. This is because their use has the potential of enhancing specific pathways of the innate and acquired immune processing and subsequent recognition of an Ag as opposed to the broader and less Ag-focused activation of the innate system in response to bacterial signals that come from of adjuvants derived from bacterial components. 

The complement-derived anaphylatoxin C5a has many prominent immune stimulatory properties and, consequently, is a good candidate for use as a molecular adjuvant. However, its use as such would be severely lunited. Describe the major limitation(s) for the use of natural C5a as a molecular adjuvant. 

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