Table 3.

Antibody concentrations (µg/ml) against three recombinant PspA proteins and against a recombinant pneumococcal surface protein A (PspA) in subjects with invasive pneumococcal disease (IPD).

	Cases (n = 15)c
GMCa (95% CI)b (µg/ml)	Acute sera	Convalescent sera	Ratio convalescent/ acute samples
Family 1, clade 2 PspA	3·2 (1·8–5·8)	21·2 (11·1–40·6)	6·6**d
Family 2, clade 3 PspA	4·2 (2·1–8·3)	15·7 (5·7–43·2)	3·7*
Family 2, clade 4 PspA	5·3 (2·7–10·1)	12·1 (5·2–28·0)	2·3**
PsaA	11·3 (4·8–27·0)	58·6 (24·7–138·8)	5·2**

^aGMC: geometric mean antibody concentration.

^bCI: confidence intervals.

^cSera missing for one patient.

^dPaired t-test:

^*P < 0·05 and

^**P < 0·01.