Immunogenicity persistence of hepatitis A vaccines Healive® and Havrix® among children:15 years follow-up and long-term prediction

Figures & data

Figure 1. Follow-up of subjects in the two groups.

Table 1. Demographic characteristics of the study population.

Time	Healive® group	Havrix® group
0 month
Subjects, no	283	92
M/F	142/141	48/44
Age, years (95% CI)	3.8(3.6–4.0)	3.7(3.4–4.0)
Height, cm (95% CI)	100.7(99.2–102.2)	100.6(97.9–103.2)
Weight, kg (95% CI)	17.2(16.8–17.7)	17.4(16.6–18.2)
138 months
Subject, no	217	73
M/F	104/113	44/29
Age, years (95% CI)	13.7(13.5–13.9)	13.6(13.2–14.0)
186 months
Subjects, no	191	57
M/F	94/97	34/23
Age, years (95% CI)	18.8(18.6–19.0)	18.5(18.3–19.1)

M/F, male/female ratio; CI, confidence interval.

Figure 2. Geometric mean concentration over time.

Figure 2 demonstrates the change of geometric mean concentrations (GMCs) for Healive® and Havrix® by months. At 0 month, the first dose was given for both groups, at 6 months the second dose was given for both groups. GMCs were measured at 18, 30, 42, 54, 66, 112, 138, and 186 months, which was 1, 2, 3, 5, 8, 11, and 15 years after full-course vaccination.

Table 2. Geometric mean concentrations and seroprotection rates over time.

Month	Healive®	Havrix®	p-value^a
1
Subjects, no	278^c	91
GMC, mIU/mL (95% CI)	29.1 (26.5–32.0)	20.3 (17.2–24.1)	<.001
SR, % (95% CI)	75.2 (69.6–80.1)	50.5 (39.9–61.2)	<.001
6
Subjects, no	282	92
GMC, mIU/mL (95% CI)	109.6 (98.4–122.1)	46.2 (38.1–56.0)	<.001
SR, % (95% CI)	97.5 (94.7–99.0)	87.0 (77.9–93.1)	<.001
7
Subjects, no	279	92
GMC, mIU/mL(95% CI)	3427.2 (3036.5–3868.1)	1441.9 (1191.1–1745.5)	<.001
SR, % (95% CI)	100.0	100.0 (95.0–100.0)	NS^b
66
Subjects, no	230	79
GMC, mIU/mL(95% CI)	257.1 (226.9–291.4)	168.1 (135.6–208.4)	.001
SR, % (95% CI)	99.1 (96.6–100.0)	97.5 (94.2–100.0)	NS
112
Subjects, no	224	75
GMC, mIU/mL(95% CI)	281.7 (248.9–318.8)	196.4 (158.0–244.1)	.004
SR, % (95% CI)	99.1 (96.5–100.0)	97.3 (89.8–100.0)	NS
138
Subjects, no	217	73
GMC, mIU/mL(95% CI)	166.8 (151.6–183.6)	117.1 (98.1–139.8)	<.001
SR, % (95% CI)	100.0 (97.8–100.0)	100.0 (93.4–100.0)	NS
186
Subjects, no	191	57
GMC, mIU/mL(95% CI)	164.8 (142.7–190.4)	105.7 (80.6–138.7)	.004
SR, %(95% CI)	97.9 (94.6–99.4)	94.7 (85.1–98.8)	NS

^aChi-square test or Fisher exact test was used to compare the seroprotection rates, and Student’s t-test was used to compare geometric mean concentrations.

^bNS, non-significant (p > .05).

^cPreviously published data are italicized.

Table 3. Comparison of Predicted GMCs and SRs based on 15-year follow-up period.

	Healive® (N = 278)				Havrix® (N = 92)
	GMC, mIU/mL (95%CI)		SR, % (95%CI)		GMC, mIU/mL (95%CI)		SR, % (95%CI)
Month	Observed	Predicted	Observed	Predicted	Observed	Predicted	Observed	Predicted
186	164.8(142.7–190.4)	141.5(128.5–155.8)	97.9(94.6–99.4)	98.5(97.8–99.2)	105.7(80.6–138.7)	94.8(79.8–112.5)	94.7(85.1–98.8)	96.1(94.2–98.0)
246	/	92.9(80.7–106.9)	/	98.0(96.9–99.0)	/	62.1(48.4–79.8)	/	94.6(91.8–97.3)
306	/	61.0(50.6–73.4)	/	97.4(96.0–98.83)	/	40.7(29.2–56.8)	/	93.1(89.4–96.8)
366	/	40.0(31.7–50.5)	/	96.87(95.10–98.8)	/	26.7(17.6–40.4)	/	91.6(87.0–96.2)
426	/	26.3(19.9–34.7)	/	96.3(94.2–98.5)	/	17.5(10.6–28.8)	/	90.1(84.5–95.6)