Analysis of antibody-negative medical students after hepatitis B vaccination in Japan

Figures & data

Table 1. Characteristics of students who received three doses of HBV vaccine for the first time

Vaccinated year	2009	2010	2011	2012	2013	2014	2015	2016	2017
Genotype of vaccine	Genotype C							Genotype A
Total number	112	117	109	123	107	102	114	113	102
Male	67	73	72	77	69	73	70	70	63
Female	45	44	37	46	38	29	44	43	39
Average age ± SD	19.5 ± 1.8	19.9 ± 1.8	20.0 ± 2.5	19.7 ± 1.8	20.0 ± 1.9	19.7 ± 2.1	20.8 ± 2.4	21.3 ± 1.4	20.3 ± 1.9
Average BMI ± SD	21.3 ± 2.7	21.9 ± 3.4	21.7 ± 2.8	21.3 ± 3.0	21.2 ± 2.8	21.6 ± 3.0	21.4 ± 2.5	21.5 ± 2.9	21.3 ± 3.2
Total number of HBsAb-negative students	15	6	2	11	6	8	6	22	18
Male	13	5	2	10	5	7	6	14	11
Female	2	1	0	1	1	1	0	8	7
BMI (average ± SD)	23.0 ± 3.4	23.9 ± 3.6	26.8 ± 6.0	25.6 ± 4.0	21.6 ± 1.6	24.7 ± 5.7	21.2 ± 1.0	22.4 ± 2.8	22.0 ± 4.2
Anti-HBs negativity ratio by genotype	6.9%							18.6%

SD: standard deviation.

Table 2. Characteristics of anti-HBs-negative students by vaccine genotype

	Genotype C	Genotype A	p^a
Total number	54	40	-
Male	48	25	-
Female	6	15	-
Average number/year ± SD	7.71 ± 4.19	20.0 ± 2.82	<0.001
Average age ± SD	20.7 ± 2.5	20.3 ± 2.2	0.98
Average BMI ± SD	23.6 ± 3.9	22.2 ± 3.4	0.07
Average of anti-HBs titer^b ± SD	4.095 ± 1.874	4.408 ± 3.129	0.68

^aBinominal t-test.

^bAnti-HBs titer data were obtained after 2013.

Table 3. Comparison between quadrisection groups by anti-HBs titer after the first course of HBV vaccination

Quadisection groups anti-HBs titer (mIU/ml)	Negative <10	Low 10–100	Middle 100–1000	High >1000
Genotype C (%)	20 (6.3)	89 (28.2)	160 (50.6)	47 (14.9)
Genotype A (%)	40 (19.2)	61 (29.3)	83 (39.9)	24 (11.6)
Male (%)	43 (12.9)	97 (29.1)	147 (44.2)	46 (13.8)
Female (%)	17 (8.9)	53 (27.8)	96 (50.2)	25 (13.1)
Average age ± SD	20.76 ± 2.77	20.15 ± 1.97	20.59 ± 10.52	19.63 ± 1.41
Average BMI ± SD	22.39 ± 3.60	21.51 ± 2.91	21.24 ± 2.75	21.01 ± 2.74

Table 4. Results of logistic regression analysis

		AOR	95% CI	p
Sex	Female	1	-
	Male	1.787	1.044–3.057	0.034
Age		1.001	0.970–1.033	0.922
BMI		1.171	1.094–1.252	<0.001
Vaccine type	Genotype C	1	-
	Genotype A	3.144	1.970–5.018	<0.001

AOR: adjusted odds ratio.

CI: confidence interval.

AICc: 555.645, BIC: 579.901, R² = 0.085.