Table 1.

Comparison of anti-HBs-positive rates between the immuni zed children and the unimmunized children

Age group (year)	Immunized children			Unimmunized children
	n	Positivea	%	n	Positivea	%
1	219	165	75.3	759	117	15.4
3	317	198	62.5	539	121	22.4
5	310	148	44.7	590	204	34.6
7	248	131	52.8	655	238	36.3
9	89	49	55.1	364	125	34.1
Total	1183	691	58.4	2907	805	27.7

^aAnti-HBs-positive was defined as S/N ratio ≥ 5.