Immunogenicity of sequential inactivated and oral poliovirus vaccines (OPV) versus inactivated poliovirus vaccine (IPV) alone in healthy infants: A systematic review and meta-analysis

Figures & data

Figure 1. Flow chart of study selection.

Table 1. Methodological quality of included RCTs.

references	Blinding	Random sequence generation	Allocation sequence concealment	Selective reporting	Incomplete outcome
Asturias, E. J. et al.	high	low	low	low	high
O'Ryan, M. et al.	high	low	low	low	low

¹ all analyses were performed in a masked manner except the study participant families and the physicians, because there were obvious variations between OPV and IPV vaccination.

² some incomplete outcome data, intent-to-treat analysis is an inappropriate approach.

Table 2. Study characteristics.

First author	Year	Country	Study period	Design type	Sample size	Participant Age	Vaccination time	Blood collection time	sequential Vaccination schedule
O'Ryan, M	2015	Chilean	April 25 to August 1, 2013	RCT	528	8 weeks (± 7 days)	8, 16, 24 weeks	28 weeks		I-bO-bO and I-I-bO
Lu, L.	2015	China	NR	case series	339	60-89 days	2, 3, 4 months	5 months		I-O-O and I-I-O
Asturias, E. J.	2007	Guatemalan	April to November 2004	RCT	292	6–11 weeks	2, 4, 6 months	7months		I-I-O
Liu, H. B.	2013	China	NR	case series	81	NP	2, 3, 4 months	5 months		I-O-O and I-I-O
Zhang, L. W.	2014	China	NR	case series	184	60-89 days	2, 3, 4 months	5 months		I-O-O and I-I-O
Faden, H.	1990	U.S.	NR	case series	86	6-10 weeks	2, 4, 12 months	13 months		I-O-O and I-I-O

NP = not reported; I = IPV; O = OPV; bO = bOPV.

Table 3. Meta-analysis for seroconversion rates between groups.

Groups		Unweighted rate n/N (percentage)	Odds radio (95% CI, p value)	I^2	Cochrane Q
Serotype 1	Sequential group	932/934 (99.79%)	1.12 (0.13, 9.73), p = 0.92	0%	0.92
	IPV-only group	574/576 (99.65%)
Serotype 2	Sequential group	583/583 (100%)	Not estimable	Not applicable	Not applicable
	IPV-only group	398/398 (100%)
Serotype 3	Sequential group	923/933 (98.93%)	0.61 (0.18, 2.08), p = 0.43	0%	0.86
	IPV-only group	572/574 (99.65%)

Figure 2. Meta-analysis plot of polio GMT against serotype 1.

Figure 3. Meta-analysis plot of polio GMT against serotype 2.

Figure 4. Meta-analysis plot of polio GMT against serotype 3.

Table 4. Quality assessment items for case series.

Quality criterions from the Centre for Reviews and Dissemination checklist
1. Were selection/eligibility criteria adequately reported?
2. Was the selected population representative of that seen in normal practice?
3. Did the study report relevant prognostic factors?
4. Were patients recruited consecutively?
5. Were patients recruited prospectively?
6. Were at least 90% of those included at baseline followed up?
7. Was loss to follow-up reported or explained?
8. Was an appropriate measure of variability reported?