Table 1.

Poliovirus Type–Specific Serum and Intestinal Antibody Responses to the Novel Type 2 Oral Poliovirus Vaccine Candidates

		N (%) or Median (IQR)a
Immune Marker by Sample Type	Day	nOPV2-c1 (n = 15)	nOPV2-c2 (n = 15)	P Valueb
Serum samples: PV type 2 serum neutralization titer	0	56.9 (36.0–181)	36.0 (22.6–90.5)	.10
	28	1150 (576–1450)	724 (362–1150)	.27
Stool samplesc
Detectable PV type 2 stool neutralization, No. (%)d	0	1 (6.7)	0 (0)	.31
	14	4 (26.7)	4 (26.7)	>.99
	21	3 (20.0)	2 (13.3)	.62
	28	5 (33.3)	5 (33.3)	>.99
	All	6 (40.0)	7 (46.7)	.71
PV type 2 stool neutralization titer	0	2 (2–2)	2 (2–2)	.32
	14	2 (2–2.7)	2 (2–2.5)	.96
	21	2 (2–2)	2 (2–2)	.59
	28	2 (2–4)	2 (2–7)	.79
PV type 2 stool IgA MFI	0	11.3 (2.0–14.1)	12.0 (3.5–17.0)	.26
	14	6.8 (3.2–22.3)	7.4 (5.6–38.1)	.42
	21	10.8 (5.0–19.5)	10.0 (2.5–46.5)	.72
	28	14.5 (2.0–29.5)	12.3 (1.5–112)	.76
PV type 1 stool IgA MFI	0	6.3 (2.0–21.5)	13.0 (5.9–22.5)	.25
	14	8.0 (1.5–11.3)	9.0 (4.4–24.0)	.42
	21	4.3 (0–8.0)	3.5 (0–16.0)	.72
	28	6.3 (0–12.0)	4.5 (0–28.0)	.68
PV type 3 stool IgA MFI	0	5.9 (3.5–31.0)	13.8 (2.0–40.5)	.56
	14	3.5 (0–15.0)	8.3 (3.4–20.0)	.16
	21	0 (0–4.8)	6.0 (0–18.5)	.15
	28	2.0 (0–14.5)	1.0 (0–18.8)	.73

Abbreviations: IgA, immunoglobulin A; IQR, interquartile range; MFI, mean fluorescence intensity; nOPV2-c1and nOPV2-c2, novel type 2 oral poliovirus vaccine candidates; PV, poliovirus.

^aData represent median (IQR) values unless otherwise specified.

^b P values based on χ ² or Mann-Whitney U tests.

^cBecause stool samples were not available for all participants on all days, we described the aggregate of the measurements obtained from samples collected days on − 2 to 0 (before vaccination) for day 0, days 12–16 for day 14, days 19–23 for day 21, and days 26–30 for day 28. If ≥2 stool samples were collected within each window for a given participant, we calculated the geometric mean of the stool neutralization titer or IgA MFI.

^dWe considered any poliovirus type 2–specific stool neutralization titer >2 to be detectable.