Decrease in Anti-HBs Antibodies over Time in Medical Students and Healthcare Workers after Hepatitis B Vaccination

Table 2

Subjects with duration of vaccination and antibody titres.

Time since vaccination; (years)	Number of subjects; (%)	Subjects protected (>10 mIU/ml); (%)	Subjects not protected (<10 mIU/ml); (%)	Antibody titre; Mean ± SD	value ANOVA
≤5	223 (65.6)	209 (94.1)	14 (5.8)		0.0001
6–10	84 (24.7)	67 (79.7)	17 (20.2)		0.0001
>10	33 (9.7)	24 (72.7)	9 (27.2)		0.0001
Total	340	300	40

between the groups (ANOVA); ≤ 5 versus 6–10 years and ≤5 versus >10 years (Bonferroni); 6–10 versus >10 years.