A phase Ⅱ, randomized, controlled trial to evaluate the safety and immunogenicity of a Sabin strain-based inactivated polio vaccine

Figures & data

Table 1. Baseline characteristics of infants participating in this study in China, 2018

Characteristic	Group A	Group B	Group C	Group D	Group E	P
Safety set
Participants, no.	119	118	119	117	118	-
Male sex, no. (%)	55(46.2)	66(55.9)	63(52.9)	59(50.4)	64(54.2)	0.606
Age (months, Mean ± SD)	2.39 ± 0.30	2.38 ± 0.30	2.38 ± 0.30	2.35 ± 0.27	2.42 ± 0.27	0.481
Per-protocol set
Participants, no.	108	105	106	103	106	-
Male sex, no. (%)	48(44.4)	58(55.2)	56(52.8)	52(50.5)	57(53.8)	0.546
Age (months, Mean ± SD)	2.37 ± 0.29	2.39 ± 0.30	2.39 ± 0.29	2.36 ± 0.27	2.43 ± 0.26	0.446

Group A: low dose Sabin IPV; Group B: medium dose Sabin IPV; Group C: high dose Sabin IPV; Group D: control Sabin IPV; Group E: control Salk IPV.

Figure 1. Profile of the clinical trial

Group A: low dose Sabin IPV; Group B: medium dose Sabin IPV; Group C: high dose Sabin IPV; Group D: control Sabin IPV; Group E: control Salk IPV.

Table 2. Seropositivity rates, seroconversion rates, GMTs and GMFIs of poliovirus type-specific neutralizing antibody in infants after three doses of vaccine in China, 2018

	Group A (N = 108)	Group B (N = 105)	Group C (N = 106)	Group D (N = 103)	Group E (N = 106)	P
Type 1 poliovirus
Seropositivity rates, %(95% CI)
Pre-vaccination	75.0(65.7, 82.8)	76.2(66.9, 84.0)	70.8(61.1, 79.2)	76.7(67.3, 84.5)	73.6(64.1, 81.7)	0.868
Post-vaccination	100.0(96.6, 100.0)	100.0(96.5, 100.0)	100.0(96.6, 100.0)	100.0(96.5, 100.0)	100.0(96.6, 100.0)	-
Seroconversion rates, %(95% CI)	99.1(94.9, 100.0)	100.0(96.5, 100.0)	99.1(94.9, 100.0)	99.0(94.7, 100.0)	93.4(86.9, 97.3)	0.004
GMTs (95% CI)
Pre-vaccination	17.6(14.1, 22.1)	17.5(14.0, 21.8)	17.4(13.6, 22.4)	21.1(16.6, 26.8)	18.6(14.6, 23.8)	0.773
Post-vaccination	3609.9(3059.1, 4259.9)	3694.9(3084.6, 4424.9)	5252.9(4436.1, 6221.6)	3894.0(3290.0, 4607.9)	693.6(584.1, 823.8)	<0.001
GMFIs (95% CI)	204.7(149.4, 280.5)	211.5(152.8, 292.8)	301.3(212.2, 427.9)	184.7(130.6, 261.3)	37.2(27.9, 49.7)	<0.001
Type 2 poliovirus
Seropositivity rates, %(95% CI)
Pre-vaccination	45.4(35.8, 55.2)	35.2(26.2, 45.2)	40.6(31.1, 50.5)	43.7(33.9, 53.8)	39.6(30.2, 49.6)	0.610
Post-vaccination	100.0(96.6, 100.0)	100.0(96.5, 100.0)	100.0(96.6, 100.0)	100.0(96.5, 100.0)	100.0(96.6, 100.0)	-
Seroconversion rates, %(95% CI)	93.5(87.1, 97.4)	97.1(91.9, 99.4)	98.1(93.4, 99.8)	95.1(89.0, 98.4)	91.5(84.5, 96.0)	0.166
GMTs (95% CI)
Pre-vaccination	8.4(7.0, 10.2)	6.9(5.8, 8.2)	7.0(6.0, 8.2)	6.9(6.0, 7.9)	6.9(5.9, 8.1)	0.518
Post-vaccination	691.2(577.0, 827.9)	801.7(685.2, 937.8)	890.2(773.6, 1024.5)	259.4(215.8, 311.7)	175.5(149.4, 206.2)	<0.001
GMFIs (95% CI)	81.8(59.8, 112.1)	116.5(88.5, 153.2)	127.2(99.4, 162.8)	37.7(29.1, 48.7)	25.3(19.5, 33.0)	<0.001
Type 3 poliovirus
Seropositivity rates, %(95% CI)
Pre-vaccination	26.7(18.8, 36.2)	21.0(13.6, 30.0)	17.0(10.4, 25.5)	27.2(18.9, 36.8)	26.4(18.3, 35.9)	0.308
Post-vaccination	100.0(96.6, 100.0)	100.0(96.5, 100.0)	100.0(96.6, 100.0)	100.0(96.5, 100.0)	100.0(96.6, 100.0)	-
Seroconversion rates, %(95% CI)	95.4(89.5, 98.5)	98.1(93.3, 99.8)	98.1(93.4, 99.8)	95.1(89.0, 98.4)	100.0(96.6, 100.0)	0.112
GMTs (95% CI)
Pre-vaccination	6.2(5.2, 7.3)	5.4(4.7, 6.2)	5.7(4.7, 6.8)	6.5(5.4, 8.0)	5.7(5.0, 6.5)	0.349
Post-vaccination	908.2(805.4, 1159.8)	1030.1(873.4, 1215.1)	1347.7(1142.6, 1589.6)	556.9(456.4, 679.5)	559.2(468.4, 667.7)	<0.001
GMFIs (95% CI)	157.1(117.8, 209.6)	191.0(146.8, 248.5)	237.8(180.6, 313.3)	85.1(61.0, 118.7)	97.8(79.0, 121.2)	<0.001

Group A: low dose Sabin IPV; Group B: medium dose Sabin IPV; Group C: high dose Sabin IPV; Group D: control Sabin IPV; Group E: control Salk IPV.

Figure 2. Distribution of post-vaccination antibody titers

Group A: low dose Sabin IPV; Group B: medium dose Sabin IPV; Group C: high dose Sabin IPV; Group D: control Sabin IPV; Group E: control Salk IPV.

Table 3. Overall adverse events in infants after three doses of vaccine in this study in China, 2018

Event, %(95% CI)	Group A (N = 119)	Group B (N = 118)	Group C (N = 119)	Group D (N = 117)	Group E (N = 118)	P
Serious adverse events *	5.0(1.9, 10.7)	2.5(0.5, 7.2)	1.7(0.2, 5.9)	4.3(1.4, 9.7)	2.5(0.5, 7.2)	0.592
Unsolicited adverse reactions
Total	0.0(0.0, 3.1)	2.5(0.5, 7.2)	0.8(0.0, 4.6)	0.9(0.0, 4.7)	0.0(0.0, 3.1)	0.170
≥Grade 3	0.0(0.0, 3.1)	0.9(0.0, 4.6)	0.0(0.0, 3.1)	0.0(0.0, 3.1)	0.0(0.0, 3.1)	0.597
Solicited adverse reactions
Total	69.8(60.7, 77.8)	71.2(62.1, 79.2)	72.3(63.3, 80.1)	70.1(60.9, 78.2)	62.7(53.3, 71.4)	0.536
≥Grade 3	1.7(0.2, 5.9)	1.7(0.2, 6.0)	0.0(0.0, 3.1)	0.0(0.0, 3.1)	1.7(0.2, 6.0)	0.369
Local adverse reactions
Redness
Total	21.9(14.8, 30.4)	23.7(16.4, 32.4)	29.4(21.4, 38.5)	16.2(10.1, 24.2)	12.7(7.3, 20.1)	0.016
≥Grade 3	1.7(0.2, 5.9)	1.7(0.2, 6.0)	0.0(0.0, 3.1)	0.0(0.0, 3.1)	0.0(0.0, 3.1)	0.219
Swelling
Total	6.7(2.9, 12.8)	6.8(3.0, 12.9)	5.0(1.9, 10.7)	0.0(0.0, 3.1)	1.7(0.2, 6.0)	0.007
≥Grade 3	1.7(0.2, 5.9)	1.7(0.2, 6.0)	0.0(0.0, 3.1)	0.0(0.0, 3.1)	0.0(0.0, 3.1)	0.219
Pain	5.0(1.9, 10.7)	6.8(3.0, 12.9)	7.6(3.5, 13.9)	0.0(0.0, 3.1)	0.9(0.0, 4.6)	0.001
Induration	7.6(3.5, 13.9)	3.4(0.9, 8.5)	5.0(1.9, 10.7)	0.9(0.0, 4.7)	2.5(0.5, 7.2)	0.087
Rash	2.5(0.5, 7.2)	1.7(0.2, 6.0)	0.8(0.0, 4.6)	0.0(0.0, 3.1)	0.9(0.0, 4.6)	0.607
Pruritus	0.8(0.0, 4.6)	0.0(0.0, 3.1)	0.8(0.0, 4.6)	0.0(0.0, 3.1)	0.9(0.0, 4.6)	1.000
Systemic adverse reactions
Fever
Total	50.4(41.1, 59.7)	50.8(41.5, 60.2)	47.1(37.8, 56.4)	48.7(39.4, 58.1)	39.0(30.1, 48.4)	0.351
≥Grade 3	0.0(0.0, 3.1)	0.0(0.0, 3.1)	0.0(0.0, 3.1)	0.0(0.0, 3.1)	0.9(0.0, 4.6)	0.597
More crying
Total	22.7(15.5, 31.3)	29.7(21.6, 38.8)	28.6(20.7, 37.6)	21.4(14.3, 29.9)	23.7(16.4, 32.4)	0.492
≥Grade 3	0.0(0.0, 3.1)	0.0(0.0, 3.1)	0.0(0.0, 3.1)	0.0(0.0, 3.1)	0.9(0.0, 4.6)	0.597
Diarrhea	15.1(9.2, 22.8)	8.5(4.1, 15.0)	16.0(9.9, 23.8)	12.0(6.7, 19.3)	12.7(7.3, 20.1)	0.451
Cough	13.4(7.9, 20.9)	15.3(9.3, 23.0)	15.1(9.2, 22.8)	16.2(10.1, 24.2)	9.3(4.7, 16.1)	0.565
Vomiting	10.1(5.3, 17.0)	7.6(3.5, 14.0)	9.2(4.7, 15.9)	9.4(4.8, 16.2)	7.6(3.5, 14.0)	0.947
Activity decline	3.4(0.9, 8.4)	4.2(1.4, 9.6)	9.2(4.7, 15.9)	6.8(3.0, 13.0)	9.3(4.7, 16.1)	0.209
Inappetence	5.9(2.4, 11.7)	4.2(1.4, 9.6)	8.4(4.1, 14.9)	4.3(1.4, 9.7)	4.2(1.4, 9.6)	0.547

Group A: low dose Sabin IPV; Group B: medium dose Sabin IPV; Group C: high dose Sabin IPV; Group D: control Sabin IPV; Group E: control Salk IPV.

* No SAE was determined relevant to the vaccination.

Table 4. Concomitant vaccination of the trial participants in this study in China, 2018

Vaccines	Group A (N = 119)	Group B (N = 118)	Group C (N = 119)	Group D (N = 117)	Group E (N = 118)	P
DTaP vaccine	80.7(72.4, 87.3)	67.8(58.6, 76.1)	67.2(58.0, 75.6)	70.9(61.8, 79.0)	72.9(63.9, 80.7)	0.141
Other vaccines*	1.7(0.2, 5.9)	0.8(0.0, 4.6)	1.7(0.2, 5.9)	0.9(0.0, 4.7)	2.5(0.5, 7.3)	0.892
Total	80.7(72.4, 87.3)	68.6(59.5, 76.9)	68.9(59.8, 77.1)	71.8(62.7, 79.7)	75.4(66.6, 82.9)	0.188

Group A: low dose Sabin IPV; Group B: medium dose Sabin IPV; Group C: high dose Sabin IPV; Group D: control Sabin IPV; Group E: control Salk IPV.

* e.g. Hib vaccine, Hep-B vaccine, 13-valent pneumonia vaccine, meningococcal polysaccharide vaccine, or OPV.