A program for eradication of hepatitis B from Taiwan by a 10-year, four-dose vaccination program.

Approximately 15 percent of the Taiwanese population are chronic carriers of hepatitis B virus (HBV), among the highest rates in Asia. In July 1984, the Taiwanese government initiated a nationwide HBV-vaccination program. The program began with educational efforts and voluntary prenatal screening for HBsAg. Infants of HBsAg-carrier mothers received a four-dose regimen of hepatitis B vaccine. Those born to highly infectious mothers also received a dose of hepatitis-B immune globulin within 24 hours after birth. Seroepidemiologic studies were conducted using a random sample of infants. Serum samples were collected at 18, 24, 36, and 48 months and analyzed via radioimmunoassay for HBsAg, anti-HBs, and anti-HBc. Infants of highly infectious mothers had HBsAg positivity rates of 14.2 percent (vaccine plus HBIG) and 19.7 percent (vaccine only) when on schedule, and 17.0 percent when off schedule. Infants of moderately infectious mothers had an HBsAg positivity rate of 3.0 percent when on schedule and 6.4 percent when off schedule. These low positivity rates persisted throughout the 48-month follow-up period. This represents a dramatic improvement upon the 40 to 96 percent vertical transmission rate seen before the program implementation. This program demonstrates that mass immunoprophylaxis for HBV is feasible, and provides practical strategies for other Asian countries.