Effect of age on the incidence of acute hepatitis B after 25 years of a universal newborn hepatitis B immunization program in Taiwan.

Background: Raising concerns about the waning immunity of cohorts receiving hepatitis B virus (HBV) vaccination in infancy persuaded us to identify the changing incidence of acute hepatitis B (AHB) in children and young adults.

Methods: Data on AHB surveillance through the National Notifiable Disease Surveillance System from July 2001 to June 2009 were collected and described. Cases were divided into 2 cohorts according to their birth year: before or after the universal newborn HBV vaccination program.

Change in hepatitis A epidemiology after vaccinating high risk children in Taiwan, 1995-2008.

Taiwan started to immunize children in 30 indigenous townships against hepatitis A since June 1995. The program was further expanded to 19 non-indigenous townships with higher incidence or increased risk of epidemic in 1997-2002, covering 2% of total population. Annual incidence of hepatitis A decreased from 2.