Table 3.

Anti-HBs titers of infants with different PVST intervals

Distribution of response*	The GMCs of anti-HBs levels (mIU/ml) (range) at different PVST intervals (month)†
	1–, (n = 191)	2–, (n = 278)	3–, (n = 220)	4–, (n = 141)	5–, (n = 95)	6–, (n = 136)	7–8, (n = 194)	Statistical analysis	P
Non-responder	7.9 (7.6–8.1)	5.7 (3.9–7.1)	3.5 (1.4–9.2)	4.4 (N/A¶)	6.7 (N/A¶)	2.5 (N/A¶)	2.6 (0.5–9.5)	χ2 = 7.134	0.309
Low-responder	59.3 (33.5–88.4)	42.1 (12.2–93.4)	56.8 (29.5–92.0)	47.0 (13.5–99.5)	45.1 (13.1–97.6)	55.6 (19.0–98.0)	42.6 (10.6–99.2)	χ2 = 4.647	0.590
Medium-responder	437.6 (108.0–996.7)	416.1 (102.8–996.6)	427.6 (102.0–994.2)	378.1 (101.4–998.9)	363.7 (113.2–912.3)	320.2 (107.3–999.0)	312.5 (100.7–946.1)	χ2 = 27.592	<0.001
High-responder§	≥1000	≥1000	≥1000	≥1000	≥1000	≥1000	≥1000	N/A	N/A

Anti-HBs, antibodies against HBsAg; PVST, postvaccination serologic testing; N/A, not applicable.

*The non-, low-, medium-, and high-responder were defined based on the anti-HBs levels <10, 10–99.9, 100–999.9, and anti-HBs ≥1000 mIU/ml, respectively.

^†Anti-HBs level was expressed in geometric mean concentration (GMC) followed by minimum and maximum values.

^§Since anti-HBs was beyond the upper detection limit (1000 mIU/ml), the GMC and range of anti-HBs titers were not calculated.

^¶Only one infant was non-responder in these three intervals and the anti-HBs range values were not applicable (N/A).