Immunogenicity and safety of a meningococcal serogroups A and C tetanus toxoid conjugate vaccine (MenAC-TT): two immune schedules in toddles aged 12–23 months in China

Figures & data

Table 1. Baseline characteristics of participants (total vaccinated cohort)

Variable		One dose group N = 150	Two doses group N = 151
Mean age at first vaccination (SD), month		18.44 (3.49)	18.59 (3.17)
Sex	Male, n (%)	88 (58.67%)	80 (52.98%)
	Female, (%)	62 (41.33%)	71 (47.02%)
BMI (95% CI)		17.05 (16.78–17.32)	16.84 (16.59–17.09)

One dose group, participants who received 1 dose at day 0; two doses group, participants who received 2 dose at day 0 and 28; N, number of participants with available results; SD, standard deviation; n (%), number (percentage) of participants in a given category; 95% CI, 95% confidence interval.

Figure 1. Flow chart for the recruitment of volunteers in the study. Titers for antibody to MenA≥1:8 pre-vaccination were two participants in the one and two doses group, respectively. Titers for antibody to MenC ≥1:8 pre-vaccination were three participants in the one and two doses group, respectively. They were removed from the analysis set (mPPS) for immunogenicity

Table 2. Percentage of participants with rSBA titers≥1:8 and ≥1:128 and geometric mean titers against the serogroups MenA and MenC (mPPS cohort for immunogenicity)

	One dose group				Two doses group
	N	titer≥1:8, %(95%CI)	titer≥1:128, %(95%CI)	GMT(95%CI)	N	titer≥1:8, %(95%CI)	titer≥1:128, %(95%CI)	GMT(95%CI)
MenA
Day 0	14	0.00	0.00	1.0	136	0.00	0.00	1.0
Day 28	144	98.61 (95.07–99.83)	90.97 (85.06–95.11)	325.7 (268.6–394.8)	135	100.00 (97.30–100.00)	85.19 (78.05–90.71)	311.2 (255.8–378.5)
Day 56	–	–	–	–	136	100.00 (97.32–100.00)	86.76% (79.89–91.96)	269.4 (228.8–317.2)
Month 12	129	71.32 (62.70–78.93)	57.36 (48.36–66.03)	53.9 (34.87–83.29)	121	79.34 (71.03–86.16)	57.85 (48.54–66.77)	67.4 (45.1–100.6)
MenC
Day 0	143	0.00	0.00	1.0	135	0.00	0.00	1.0
Day28	143	97.20 (92.99–99.23)	84.62 (77.64–90.10)	227.9 (180.3–288.1)	134	99.25 (95.91–99.98)	81.34 (73.70–87.55)	206.0 (166.1–255.6)
Day56	–	–	–	–	135	98.52 (94.75–99.82)	81.48 (73.89–87.64)	177.6 (147.2–214.3)
Month12	128	78.13 (69.96–84.95)	29.69 (21.94–38.40)	29.2 (19.8–42.9)	120	80.83 (72.64–87.44)	26.67 (19.01–35.51)	26.14 (18.7–36.6)

One dose group, participants who received 1 dose at day 0; two doses group, participants who received 2 dose at day 0 and 28; N, number of participants with available results; day 0, the day of first dose; day 28, 28 days post the first dose; day 56, 56 days post the first dose; month 12, 12 month post the first dose; 95% CI, 95% confidence interval.

Table 3. Common symptoms analysis of solicited local and systemic ARs occurring after vaccination

			Total (%)			Grade1			Grade2			Grade3
Symptom	Group	N	%	χ^2	P	%	χ^2	P	%	χ^2	P	%		χ^2	P
Adverse action	One dose group	150	44.00	6.1396	0.0132	29.33	0.1146	0.7349	10.67	9.9304	0.0016	3.33		^a	0.7497
	Two dose group	151	58.28			31.13			24.50			2.65
Pain	One dose group	150	2.67	^a	1.0000	0.67	^a	0.3708	0.67	^a	0.4983	1.33		^a	0.2475
	Two dose group	151	2.65			2.65			0.00			0.00
Induration	One dose group	150	4.00	0.0001	0.9906	1.33	^a	1.0000	0.67	^a	0.6225	1.33		^a	0.6225
	Two dose group	151	3.97			1.33			1.99			0.66
Redness	One dose group	150	10.67	7.6282	0.0057	6.00	4.5368	0.0332	3.33	3.7254	0.0536	1.33		^a	0.6225
	Two dose group	151	22.52			13.25			8.61			0.66
Swelling	One dose group	150	10.00	0.2843	0.5939	6.67	0.4024	0.5259	0.67	^a	0.3708	2.67		^a	0.2141
	Two dose group	151	11.92			8.61			2.65				0.66
Pruritus	One dose group	150	2.67	^a	1.0000	1.33	^a	1.0000	0.67	^a	1.0000		0.67	^a	0.4983
	Two dose group	151	2.65			1.99			0.66				0.00
Fever	One dose group	150	29.33	3.1711	0.0750	19.33	0.1609	0.6883	8.00	4.4533	0.0348		2.00	^a	1.0000
	Two dose group	151	39.07			21.19			15.89				1.99
Allergic reaction	One dose group	150	0.00	^a	1.0000	0.00	–	–	0.00	^a	1.0000		0.00	–	–
	Two dose group	151	0.66			0.00			0.66				0.00
Dysphoria	One dose group	150	0.00	^a	1.0000	0.00	^a	0.2475	0.00	^a	1.0000		0.00	–	–
	Two dose group	151	2.65			1.99			0.66				0.00
Diarrhea	One dose group	150	3.33	0.0876	0.7673	2.67	^a	0.7497	0.67	^a	0.4983		0.00	–	–
	Two dose group	151	3.97			3.97			0.00				0.00
Fatigue	One dose group	150	0.67	^a	0.6225	0.67	^a	1.0000	0.00	^a	1.0000		0.00	–	–
	Two dose group	151	1.99			1.33			0.66				0.00
Loss of appetite	One dose group	150	2.00	^a	1.0000	1.33	^a	1.0000	0.67	^a	1.0000		0.00	_	_
	Two dose group	151	1.99			1.33			0.66				0.00

^aFisher’s exact test; –: Not applicable; One dose group, participants who received 1 dose at day 0; two doses group, participants who received 2 dose at day 0 and 28; N, number of participants with available results; the common symptoms were compared at day 28 in one dose group and day 28 post-dose 2 in the two dose group.

Table

IMD	invasive meningococcal disease
MenA	meningococcal serogroups A
MenC	meningococcal serogroups C
MenAC-TT	meningococcal Serogroups A and C tetanus toxoid conjugate vaccine
EPI	expanded program on immunization
MCC	meningococcal serogroup C conjugate vaccine
MenACYW–D	meningococcal polysaccharide diphtheria toxoid conjugate vaccine
AE	adverse event
AR	adverse reaction
GMT	geometric mean titer
SAE	serious adverse event
CI	confidence interval
mPPS	modified per-protocol set
IEC	independent ethics committee
CFDA	Chinese Food and Drug Administration
GCP	Good Clinical Practice
GCLP	Good Clinical Laboratory Practice
JSCDC	Jiangsu Provincial Center for Disease Control and Prevention