Table 2.

Hepatitis B surface antigen prevalence before and after the introduction of universal vaccination for hepatitis B virus

Ref.	Region	Country		Subjects	Year of the introduction of infant universal vaccination	HBsAg positive rate
						Before-vaccination program	Year	After vaccination program	Year
95	North America	United States	(Hawai)	School children	1992	1.6%	1989	0.04%	2001-2002
96	South America	Colombia	(Colombian Amazon)	5-9 yr of age	1992	7%	1992	2%	1999
97	Asia	Taiwan	(Taipei)	≤ 12 yr of age	1984	9.8%	1984	1.3%	1994
94	Asia	China		Young children	1992	9%-12%	1992	< 1%	2005
98	Europe	Italy	(Afragola)	General population	1991	13.4%	1978	0.91%	2006
99	Africa	South Africa	(Gauteng Province)	≤ 24 mo after birth	1995	8%-9%	1995-1996	0.9%	2003-2004
100	Africa	Gambia	(Keneba)	≤ 24 yr of age	1984	13.3%	1984	0.6%	2003
100	Africa	Gambia	(Mandar)	≤ 24 yr of age	1984	35%	1984	1%	2003