Immunoprophylaxis failure and vaccine response in infants born to mothers with chronic hepatitis B infection in Djibouti

Table 1 Sociodemographic characteristics of the hepatitis B surface antigen-positive pregnant women, n = 50

Variables	Frequency	%
Age of mother in yr, n = 46
18-20	1	2
20-30	21	46
30-40	21	46
> 40	3	6
Mother occupation
Employed	31	62
Unemployed	19	38
Mother education level
Illiterate	22	44
Primary	5	10
Secondary	18	36
University	5	10
Parity
Nulli or primiparous 0-1	7	14
Multiparous 1-3	31	62
Large multiparous	12	24
First antenatal care
1 trimester	16	32
2 trimester	16	32
3 trimester	18	36
History of blood transfusion
Yes	14	28
No	36	72
History of abortion
Yes	15	30
No	35	70
Family history of HBV
Yes	17	34
No	33	66
Vaccination against HBV
Yes	0	0
No	50	100
Marital status of mother
Married	50	100
Not married	0	0
Monitoring by a health care worker
Yes	50	100
No	0	0
HBeAg status of mother
Negative	47	94
Positive	3	4
Viral load HBV DNA
< 200000	47	94
> 200000	3	6

HBeAg: Hepatitis B e antigen; HBV: Hepatitis B virus.

Table 2 Biological status of the infants and response to immunization

Variables	Frequency	%
Infants birth weight
< 2500 g	9	18
2500-3500 g	36	72
> 3500 g	5	10
Delivery mode
Vaginal	39	78
Cesarean	11	12
Sex of infants
Male	32	64
Female	18	36
HBIG + Hep B-BD vaccine
Yes	50	100
No	0	0
Vaccination Hep B3 (penta 1, 2, 3)
Yes	50	100
No	0	0
Response to vaccine
< 100	33	84
≥ 100	5	16
Negative	2	NA
Immunoprophylaxis failure
Yes	2	4
No	48	96

HBIG: Hepatitis B immunoglobulin; Hep B-BD: Hepatitis B Birth Dose; Hep B3: Pentavalent vaccine hepatitis B vaccine administered at 6 wk, 10 wk, and 14 wk of age; NA: Not available.

Table 3 Characteristics of two hepatitis B virus-infected children born to hepatitis B surface antigen-positive mother

Characteristics	Infant 1	Infant 2
Mother data
Age of mother	34	32
Education level	Illiterate	Illiterate
Family history of HBV	Yes	Yes
Blood transfusion	No	No
Parity of mother	Multiparous	Large multiparous
First antenatal care	3 trimester	3 trimester
History of abortion	No	No
HBV DNA	> 200000 UI/mL	> 200000 UI/mL
HBeAg status	Positive	Positive
Infant data
Birth weight	3.5 kg	2.5-3.5 kg
Delivery mode	Vaginal	Vaginal
Birth rank	2	3
Sex	Male	Male
HBIG + Hep B-BD	Yes	Yes
Hep B3 (penta 1,2, and 3)	Yes	Yes

HBeAg: Hepatitis B e antigen; HBIG: Hepatitis B immunoglobulin; HBV: Hepatitis B virus; Hep B-BD: Hepatitis B Birth Dose; Hep B3: Pentavalent vaccine hepatitis B vaccine administered at 6 wk, 10 wk, and 14 wk of age.

Table 4 Analysis of risk factors for failure of immunoprophylaxis

Variables	No failure, n = 48	Failure, n = 2	χ2	P value	OR (95%CI)	P value
HBV DNA of mother			32.64	< 0.001
> 200000 IU/mL	1 (2.1)	2 (100)			Reference
< 200000 IU/mL	47 (97.9)	0 (0)		-	158.00 (5.05-49.80)	0.004
Mother HBeAg status			32.64	< 0.001
Negative	47 (97.9)	0 (0)			Reference
Positive	1 (2.1)	2 (100)		-	158.00 (5.05-49.80)	0.004
Family history of HBV			1.07	0.300
No	31 (65.0)	2 (100)			Reference
Yes	17 (35.0)	0 (0)		-	0.36 (0.20-198.00)	0.517
History of abortion			0.89	0.340
No	33 (69.0)	2 (100)			Reference
Yes	15 (31.0)	0 (0)		-	0.43 (0.02-9.55)	0.595
Delivery mode in infants			0.59	0.440
Vaginal	37 (77.0)	2 (100)			Reference
Cesarean	11 (23.0)	0 (0)		-	1.50 (0.06-34.00)	0.780
Parity of mother			0.93	0.630
Null parous	7 (15.0)	0 (0)			Reference
Multiparous	30 (62.0)	1 (50.0)		-	0.73 (0.27-19.00)	0.181
Large multiparous	11 (23.0)	1 (50.0)		-	1.95 (0.07-54.00)	0.693
Infant birth weight			1.53	0.460
2.5-3.5 kg	35 (73.0)	1 (50.0)			Reference
< 2.5 kg	8 (17.0)	1 (50.0)		-	4.37 (0.25-77.65)	0.315
> 3.5 kg	5 (10.0)	0 (0)		-	2.15 (0.08-59.70)	0.651
Infant sex			1.17	0.280
Male	30 (62.0)	2 (100)			Reference
Female	18 (38.0)	0 (0)		-	0.54 (0.12-2.49)	0.428
Blood transfusion			0.50	0.490
No	35 (73.0)	1 (50.0)			Reference
Yes	13 (27.0)	1 (50.0)		-	2.69 (0.16-46.00)	0.495
First antenatal care of mother			3.70	0.157
1 trimester	16 (33.0)	0 (0)			Reference
2 trimester	16 (33.0)	0 (0)		-	0.02-53.40	1.000
3 trimester	16 (33.0)	2 (100)		-	5 (0.22-112.00)	0.310

Data are n (%). CI: Confidence interval; HBeAg: Hepatitis B e antigen; HBV: Hepatitis B virus; OR: Odds ratio.

Table 5 Risk factor analysis for low immune responses

Variable	AcHBs Vt ≥ 100 mUI/mL	AcHBs Vt < 100 mUI/mL1	χ2	P value	OR (95%CI)	P value
HBV DNA			0.20	0.650
> 200000 IU/mL	1 (2.5)	0 (0)			Reference	0.794
< 200000 IU/mL	39 (97.5)	8 (100)		-	1.54 (0.05-41.38)
HBeAg status			0.20	0.650
Negative	39 (97.5)	8 (100)			Reference
Positive	1 (2.5)	0 (0)		-	1.54 (0.05-41.38)	0.794
Antecedent HBV			0.46	0.500
No	25 (62.0)	6 (75.0)			Reference
Yes	15 (38.0)	2 (25.0)		-	0.56 (0.10-3.11)	0.504
History of abortion			4.36	0.370
No	25 (62.0)	8 (100)			Reference
Yes	15 (38.0)	0 (0)		-	0.09 (0.01-1.79)	0.117
Mode of delivery			0.59	0.440
Cesarean	10 (25.0)	1 (12.0)			Reference
Vaginal	30 (75.0)	7 (88.0)		-	2.33 (0.25-21.36)	0.453
Birth weight in kg			17.97	< 0.001
2.5-3.5	34 (85.0)	1 (12.0)			Reference
< 2.5	4 (10.0)	4 (50.0)		-	34 (3.01-383.86)	0.004
> 3.5	2 (5.0)	3 (38.0)		-	51 (3.51-740.17)	0.004
Infant sex			1.17	0.420
Male	26 (65.0)	4 (50.0)			Reference
Female	14 (35.0)	4 (50.0)		-	0.54 (0.12-2.49)	0.428

Data are n (%).

¹Low immune response. AcHBs: Hepatitis B surface antibody; CI: Confidence interval; HBeAg: Hepatitis B e antigen; HBV: Hepatitis B virus; OR: Odds ratio; Vt: Viral titer.