Long-term efficacy of plasma-derived hepatitis B vaccine among Chinese children: a 12-year follow-up study

Table 2 Hepatitis B infections at each follow-up observation

Time since first dose	% of HBsAg			% of anti-HBc
	Vaccinated group	Control group	Efficacy (%)	Vaccinated group	Control group	Efficacy (%)
6 months	2.9	7.4	60.8	5.9	10.8	45.4
1 year	3.4	3.9		2.5	13.4c	81.3
2 years	1.2	8.6a	86.0	2.5	24.7d	89.9
3 years	1.0	10.4c	90.4	12.2	29.6b	58.8
5 years	0.0	14.6c	100.0	1.3	24.0d	94.6
8 years	5.9	13.6	56.6	7.8	23.7b	67.1
10 years	1.3	14.6c	91.1	1.3	14.6c	91.2
12 years	1.8	10.9c	83.5	9.6	37.7d	74.5

^aP < 0.1 and > 0.05;

^bP < 00.05;

^cP < 0.01;

^dP < 0.0001.