Tab. I.

Demographic and epidemiological characteristics.

	Anti-HBs < 10 mIU/mL (N = 172)	Anti-HBs ≥ 10 mIU/mL (N = 449)	P-value
Gender Male (n, %) Female (n, %)	74, 43.0% 98, 57.0%	170, 37.9% 279, 62.1%	n.s. n.s.
Age at HBV vaccination Infancy (0-3 years), % Adolescence (10-16 years), %	89.5 10.5	46.1 53.9	< 0.001
Vaccine dose Pediatric, % Adult, %	94.2 5.8	64.1 35.9	< 0.001
Time since vaccination mean ± SD (years)	20.4 ± 2.2	18.3 ± 3.2	< 0.001
Age at testing mean ± SD (years)	22.6 ± 2.4	25.3 ± 3.4	< 0.001