Effect of the interval between birth and second dose of hepatitis B vaccine on perinatal transmission of hepatitis B virus

Figures & data

Table 1. Bivariate analysis on factors associated with immunoprophylaxis failure among infants born to HBV-infected mothers, stratified by the interval between HepB-BD and HepB-SD, Republic of Korea, 2002–2013.

	Infants, n				Interval HepB-BD – HepB-SD 4–<8 weeks				Interval HepB-BD – HepB-SD ≥8 weeks
		HBsAg-positive infants			Infants, n	HBsAg-positive infants			Infants, n	HBsAg-positive infants
		n	%	p-value		n	%	p-value		n	%	p-value
Overall	39,313	1,027	2.6		38,907	1,013	2.6		406	14	3.4
Maternal age
<25 years	2,451	135	5.5	<.001	2,415	133	5.5	<.001	36	2	5.6	.636
25–29 years	14,906	419	2.8		14,774	416	2.8		132	3	2.3
30–34 years	17,091	368	2.2		16,906	362	2.1		185	6	3.2
≥35 years	4,865	105	2.2		4,812	102	2.1		53	3	5.7
Maternal nationality
Korean	37,621	932	2.5	<.001	37,250	919	2.5	<.001	371	13	3.5	1.000
Non-Korean	1,692	95	5.6		1,657	94	5.7		35	1	2.9
Maternal HBeAg status
HBeAg-negative	25,106	195	0.8	<.001	24,854	192	0.8	<.001	252	3	1.2	.002
HBeAg-positive	14,207	832	5.9		14,053	821	5.8		154	11	7.1
Sex of infants
Female	19,234	486	2.5	.312	19,038	477	2.5	.254	196	9	4.6	.287
Male	20,079	541	2.7		19,869	536	2.7		210	5	2.4
Gestational length
24–36 weeks’ gestation	1,811	34	1.9	.048	1,789	33	1.8	.043	22	1	4.5	1.000
37–42 weeks’ gestation	37,502	993	2.6		37,118	980	2.6		384	13	3.4
Infant birth weight
<2,000 g	39,295	1025	2.6	.071	17	2	11.8	.068	1	0	0.0	1.000
≥2,000 g	18	2	11.1		38,890	1011	2.6		405	14	3.5
Delivery type
Vaginal delivery	14,198	338	2.4	.035	24,856	679	2.7	.044	259	10	3.9	.582
Caesarean section	25,115	689	2.7		14,051	334	2.4		147	4	2.7
Timing of HepB-BD
Administered at Day 0	38,411	1004	2.6	1.000	38,014	991	2.6	.956	397	13	3.3	.273
Administered at Day 1	429	11	2.6		424	10	2.4		5	1	20.0
Administered at Day 2+	473	12	2.5		469	12	2.6		4	0	0.0
Timing of HepB-SD after HepB-BD
<4 weeks	580	21	3.6	.315	N/A				N/A
4–<8 weeks	38,327	992	2.6
8–<12 weeks	301	11	3.7
≥12 weeks	105	3	2.9
Timing of HepB-TD after HepB-SD
<4 weeks	5	0	0.0	.228	2	0	0.0	.731	3	0	0.0	.364
4–<20 weeks	546	20	3.7		330	10	3.0		216	10	4.6
≥20 weeks	38,762	1007	2.6		38,575	1003	2.6		187	4	2.1
HBIg
No	71	2	2.8	1.000	67	2	3.0	1.000	4	0	0.0	1.000
Yes	39,242	1025	2.6		38,840	1011	2.6		402	14	3.5

Abbreviations: HepB-BD, hepatitis B birth-dose vaccine; HepB-SD, hepatitis B second-dose vaccine; HepB-TD, hepatitis B third-dose vaccine; HBeAg, hepatitis B e antigen; HBIg, hepatitis B immune globulin; HBsAg, hepatitis B surface antigen; N/A, not applicable.

Data excluded infants with interval of HepB-BD – HepB-SD <4 weeks and infants who were tested for HBsAg before 9 months after birth.

Table 2. Univariable and multivariable analyses for factors associated with the risk of perinatal HBV infection among infants born to HBV-infected mothers, Republic of Korea, 2002–2013.

	Univariate analysis			Multivariate analysis
	Crude OR	(95% CI)	p-value	Adjusted OR	(95% CI)	p-value
Second dose schedule <8 weeks (vs. ≥8 weeks)	0.75	(0.44–1.28)	.290	0.79	(0.46–1.37)	.405
Maternal age (vs. ≥35 years)
<25 years	2.64	(2.04–3.43)	<.001	1.52	(1.14–2.02)	.004
25–29 years	1.31	(1.06–1.63)	.014	1.06	(0.85–1.32)	.591
30–34 years	1.00	(0.80–1.24)	.983	0.91	(0.73–1.14)	.413
Non-Korean mother (vs. Korean mother)	2.34	(1.89–2.91)	<.001	1.56	(1.22–2.01)	<.001
Maternal HBeAg-positive (vs. maternal HBeAg-negative)	7.95	(6.79–9.30)	<.001	7.66	(6.54–8.98)	<.001
Male infant (vs. female infant)	1.07	(0.94–1.21)	.298
Short gestational length (24–36 weeks)(vs. 37–42 weeks)	0.70	(0.50–0.99)	.046	0.68	(0.48–0.96)	.029
Low birth weight (500–<2,000 g) (vs. ≥2,000 g)	4.67	(1.07–20.32)	.040
Vaginal delivery (vs. Caesarean section)	1.16	(1.01–1.32)	.030	0.94	(0.82–1.08)	.382
Timing of BD (vs. Day 0)
Day 1	0.98	(0.54–1.79)	.949
Day 2+	0.97	(0.54–1.73)	.917
Timing of HBIg (vs. Day 0)
Day 1	0.93	(0.51–1.69)	.803
Day 2+	0.95	(0.54–1.64)	.842
Never	1.08	(0.26–4.41)	.916

Abbreviations: CI, confidence interval; HepB-BD, hepatitis B birth-dose vaccine; HepB-SD, hepatitis B second-dose vaccine; HepB-TD, hepatitis B third-dose vaccine; HBeAg, hepatitis B e antigen; HBIg, hepatitis B immune globulin; HBsAg, hepatitis B surface antigen; OR, odds ratio.

Data availability statement

Study’s supporting data not public; available on request from TUY.