Table 2.

Antibody concentration strata for participants with measurable neutralising antibodies

		Participants		Neutralising antibodies (IU/mL)
		n (%, 95% CI)	Percentage of seropositive participants	Geometric mean (95% CI)	Median (IQR)
Seropositive participants (antibody concentration ≥0·5 IU/ml)
Mali, year 4·5, n=587
	Total	296 (50·4%, 46·4–54·5)	100·0%	1·120 (1·040–1·210)	0·915 (0·702–1·440)
	Low tier	242 (41·2%)	81·8%	0·863 (0·826–0·902)	0·882 (0·610–1·210)
	High tier	54 (9·2%)	18·2%	3·530 (3·100–4·070)	2·890 (2·420–4·640)
Ghana, year 2·3, N=436
	Total	121 (27·8%, 23·5–32·0)	100·0%	1·380 (1·170–1·660)	1·020 (0·721–2·030)
	Low tier	90 (20·6%)	74·4%	0·854 (0·792–0·922)	0·765 (0·610–1·210)
	High tier	31 (7·1%)	25·6%	5·560 (4·110–7·790)	4·080 (2·890–8·160)
Ghana, year 6·0, n=436
	Total	188 (43·1%, 38·5–47·8)	100·0%	1·790 (1·550–2·080)	1·440 (0·854–2·870)
	Low tier	110 (25·2%)	58·5%	0·915 (0·856–0·978)	0·911 (0·647–1·210)
	High tier	78 (17·9%)	41·5%	4·610 (3·810–5·670)	2·890 (2·350–7·800)
Borderline participants (measurable antibody concentration <0·5 IU/ml)
Mali, year 4·5		113 (19·3%, 16·1–22·4)	NA	0·335 (0·318–0·353)	0·361 (0·271–0·453)
Ghana, year 2·3		51 (11·7%, 8·7–14·7)	NA	0·359 (0·337–0·382)	0·381 (0·312–0·430)
Ghana, year 6·0		35 (8·0%, 5·5–10·6)	NA	0·334 (0·309–0·361)	0·361 (0·302–0·383)
Broadly seropositive participants (all participants with a measurable antibody concentration)
Mali, year 4·5		409 (69·7%, 66·0–73·4)	NA	0·801 (0·742–0·865)	0·721 (0·457–1·220)
Ghana, year 2·3		172 (39·4%, 34·9–44·0)	NA	0·926 (0·796–1·090)	0·721 (0·455–1·400)
Ghana, year 6·0		223 (51·1%, 46·5–55·8)	NA	1·380 (1·190–1·600)	1·170 (0·640–2·360)

The low and high tiers of seropositive participants are differentiated at the 1·8 IU/ml or more threshold. NA=not applicable.