Table 6. HBsAg seropositivity and HBsAg annual seroclearance in the participants who participated in both serologic surveys.

Participants	Number	HBsAg Seropositive		p-Value	Person-Years under Observationa	HBsAg Annual Seroclearanceb
		Number	Rate (%)
Vaccination group
Age 10–11 years	10,051	184	1.83	0.5938	2,760	0.36%
Age 19–28 years		174	1.73
Control group without catch-up vaccination
Age 10–11 years	1,019	95	9.32	0.1516	1,655	1.09%
Age 19–28 years		77	7.56
Control group with catch-up vaccination
Age 10–11 years	4,971	420	8.45	0.0008	6,019	1.46%
Age 19–28 years		332	6.68

^aHBsAg-positive participants.

^bHBsAg annual seroclearance rates were calculated by dividing the number of incident cases of HBsAg seroclearance by person-years of follow-up.