Table 2.

Typhi Vi concentrations and fold increase in concentrations in healthy volunteers and individuals with antibody deficiency. *Refers to intra‐assay %CV.

		Healthy volunteers	Antibody‐deficient patients
		Typhim Vi® (U/ml)	Typhim Vi® (U/ml)
Pre‐vaccination (U/ml)	n	8*	20*
	Range	< 7·4–14	< 7·4–16
Post‐vaccination U/ml)	n	8	12
	Median	107	23
	range	31–542	10–372
Fold increase in concentration (FI)
	FI > 3	8/8 (100%)	6/20 (30%)
	FI > 10	6/8 (75%)	2/20 (10%)

Typhim Vi^® antibodies were measured in serum samples obtained from healthy volunteers and antibody deficiency patients as described in the Materials and methods. *Three individuals with high baseline concentrations of Typhi Vi immunoglobulin (Ig)G were removed for generation of reference ranges.