Table 1.

Number of subjects available for analysis from studies with serotype 2 baseline immunogenicity measures and pre-challenge stool viral shedding quantities, by regimen, for studies IPV001 [11] and IPV002 [9]. All subjects were challenged with mOPV2 4 weeks following final vaccination, except for IPV001 Group 2, who were challenged 26 weeks following their last vaccination.

Study	Group	Regimen	Schedule	N‡	Seroprotection rate*	Median NAb titre (log2)*	Pre-challenge shedding positivity**	Median log10 viral titer among shedders**
IPV001	1	bOPV-bOPV-bOPV	6-10-14 wks	187	113/209 (54.1%)	3.2	1/18 (5.6%)	3.2
	2	bOPV-bOPV-bOPV	6-10-14 wks	179	124/210 (59.0%)	3.2	0/13 (0.0%)	N/A
	4/6/8†	bOPV-bOPV-bOPV + IPV	6-10-14 wks 14 wks	274	175/310 (56.5%)	3.5	2/28 (7.1%)	3.8
	5/7/9†	bOPV-bOPV-bOPV + IPV-IPV	6-10-14 wks 14-36 wks	519	327/590 (55.4%)	3.2	1/63 (1.6%)	4.1
	3	tOPV-tOPV-tOPV	6-10-14 wks	81	62/99 (62.6%)	3.5	1/15 (6.7%)	3.8
IPV002	1	IPV–bOPV–bOPV	2-4-6 months	150	117/182 (64.3%)	3.5	5/174 (2.9%)	3.2
	2	IPV–IPV–bOPV	2-4-6 months	166	114/187 (61.0%)	3.5	2/181 (1.1%)	6.3
	3	IPV–IPV–IPV	2-4-6 months	165	119/185 (64.3%)	3.8	3/177 (1.7%)	2.9

^‡Number with available data for both pre-challenge serology and post-challenge shedding index endpoint (SIE).

^*Immediately prior to first vaccination.

^**4 weeks after last vaccination, immediately prior to mOPV2 challenge dose.

^†Combined across manufacturer group.