Table 2.

The pros and cons of potential typhoid vaccine adjuvants

Adjuvant	Tradenames	Pros	Cons
Aluminum salts (Alum)	AdjuPhos®, Alhydrogel®	• Low cost • Easy to formulate • Enhances anti-Vi response	• Imparts major Th2 immune bias which may predispose to allergy/anaphylaxis • Does not overcome polysaccharide-associated immune suppression • Only modest enhancement of Vi antibody titers • Low efficacy in children aged <3 months
Delta inulin-CpG oligonucleotide combination adjuvant	Advax-CpG™	• Low cost • Easy to formulate • Overcomes polysaccharide-associated immune suppression • Strong enhancement of anti-Vi response • Induces production of serum bactericidal antibodies • Effectively overcomes neonatal immune hypo-responsiveness in newborns	• None