A randomized, controlled, blinded study of the safety and immunogenicity of Haemophilus influenzae type b conjugate vaccine injected at different intramuscular sites in Chinese infants

Figures & data

Table 1. Numbers and mean ages of infants in the study groups

Age group	Injection site	No. of subjects	Mean age ± SD (months)	No. completing observations	No. with paired serum samples
2–5 mo	Deltoid	80	2.74 ± 1.05*	70	70
	Vastus lateralis	80	2.58 ± 0.92	73	73
6–12 mo	Deltoid	80	8.48 ± 1.42^†	76	71
	Vastus lateralis	80	8.30 ± 1.58	79	76

* p = 0.490 vs vastus lateralis group. ^†p = 0.471 vs vastus lateralis group.

Table 2. GMCs of Hib-PRP antibodies before immunization in the vastus lateralis (experimental) and deltoid (control) groups

Age group	Injection site	No. of subjects	Antibody GMCs (μg/mL)	P value
2–5 mo	Deltoid	70	0.36 ± 0.48	0.374
	Vastus lateralis	73	0.37 ± 0.50
6–12 mo	Deltoid	71	0.87 ± 0.91	0.648
	Vastus lateralis	76	0.67 ± 1.34

GMC, geometric mean concentration; Hib, Haemophilus influenzae type b; PRP, polyribosylribitol phosphate.

Table 3. Antibody protection rates after immunization in the experimental (vastus lateralis) and control (deltoid) groups

Age group	Injection site	No. of subjects	Hib-PRP antibody GMC			Hib-PRP antibody GMC
			≥ 1.0 μg/mL			≥ 0.15 μg/mL
			No.	Percentage	P value	No.	Percentage	P value
2–5 mo	Deltoid	70	67	95.71	1	70	100	‒
	Vastus lateralis	73	70	95.89		73	100
6–12 mo	Deltoid	71	69	97.18	1	71	100	‒
	Vastus lateralis	76	74	97.37		76	100

GMC, geometric mean concentration; Hib, Haemophilus influenzae type b; PRP, polyribosylribitol phosphate.

Table 4. GMCs of Hib-PRP antibodies after immunization of the experimental (vastus lateralis) and control (deltoid) groups

Age group	Injection site	No. of subjects	Antibody GMCs (μg/mL)	P value
2–5 mo	Deltoid	70	5.13 ± 42.95	0.755
	Vastus lateralis	73	5.33 ± 43.76
6–12 mo	Deltoid	71	2.49 ± 29.57	0.276
	Vastus lateralis	76	3.07 ± 33.31

GMC, geometric mean concentration; Hib, Haemophilus influenzae type b; PRP, polyribosylribitol phosphate.

Table 5. Local reactions during 28 d after each vaccination in the experimental (vastus lateralis) and control (deltoid) groups

Age group	Injection site	No. of subjects	No. with local reactions			Percentage (total)	χ^2	P value
			Induration	Redness	Swelling
• Following the first dose:
2–5 mo	Deltoid	70	1	6	1	11.43	0.805	0.370
	Vastus lateralis	73	0	9	3	16.67
6–12 mo	Deltoid	76	0	0	0	0	‒	‒
	Vastus lateralis	79	0	0	0	0
• Following the second dose:
2–5 mo	Deltoid	70	0	0	0	0	‒	‒
	Vastus lateralis	73	0	0	0	0
6–12 mo	Deltoid	76	0	0	0	0	‒	‒
	Vastus lateralis	79	0	0	0	0
• Following the third dose:
2–5 mo	Deltoid	70	0	1	0	1.43	1.036	0.309
	Vastus lateralis	73	0	0	0	0

Table 6. Systemic reactions during 28 d after each vaccination in the experimental (vastus lateralis) and control (deltoid) groups

Age group	Injection site	No. of subjects	No. with systemic reactions								Percentage (total)	χ^2	P value
			Fever	Rash	Vomiting	Abnormal crying	Somnol- ence	Loss of appetite	Irritab- ility	Other
• Following the first dose:
2–5 mo	Deltoid	70	11	2	1	9	3	4	11	1	60.00	1.434	0.231
	Vastus lateralis	73	4	0	0	17	0	3	12	0	50.00
6–12 mo	Deltoid	76	0	0	0	0	0	0	0	0	0	‒	‒
	Vastus lateralis	79	0	0	0	0	0	0	0	0	0
• Following the second dose:
2–5 mo	Deltoid	70	0	0	0	0	0	1	0	0	1.43	1.779	0.182
	Vastus lateralis	73	0	0	0	1	0	1	2	0	5.56
6–12 mo	Deltoid	76	0	0	0	0	0	0	0	0	0	‒	‒
	Vastus lateralis	79	0	0	0	0	0	0	0	0	0
• Following the third dose:
2–5 mo	Deltoid	70	2	1	0	1	0	1	1	0	8.57	5.924	0.015
	Vastus lateralis	73	0	0	0	0	0	0	0	0	0