Rocks Along the Road to the Control of HBV and HCC

Hepatitis B vaccine is one of the best human vaccines ever developed; it is safe, cheap, and highly immunogenic, stimulates long lasting protective efficacy, and is the first human cancer vaccine. Remarkably, HBV vaccine works even when administered to newborns, timing which is necessary because of mother to infant transmission. Countrywide HBV immunization programs were initiated in Taiwan and Thailand in the 1980s. HBV vaccine has been part of the WHO global immunization since 199x and with at-birth immunization programs in xxx countries resulting in major declines in acute sequelae of HBV infection. Of far greater significance, HBV vaccination prevents hepatocellular carcinoma (HCC) and its use is reducing mother to infant transmission, the driving force behind the HBV carrier state worldwide. These benefits are just being realized since decades elapse between perinatal transmission at birth and the onset of HCC decades later. Studies in Taiwan and Thailand are showing declines in HCC incidence as a result of country wide at-birth HBV immunization programs initiated in the 1980s. Many investigators from many countries have contributed to the understanding of HBV and its role as the major cause of HCC. This article briefly summarizes the work of my University of Washington laboratory in Taipei, Taiwan where I lived and worked from 1972 and 1986 because of the very high HBV carrier rates of HBV in Taiwan. During those 14 years we discovered vertical transmission, its timing and mechanism, and the predictive value of HBcAg. We went on to establish the efficacy of HBIG for prevention of vertical transmission. In later Studies we established the efficacy and timing of HBV vaccine and HBIG and HBV vaccine in combination for optimum preventive efficacy. Of greatest significance, our studies showed that chronic HBV infection is the commonest cause of HCC. Worldwide, mothers are the driving force behind the infections that lead to HCC because the HBV carrier state is inversely proportional to the age of the infant when infected. We were able persuade WHO to adopt HBV as the 7th immunogen in the EPI, its global infant immunization program. In some ways enormous progress has been made but measured against its potential, progress in most countries, including the United States has been far too slow. Ann Epidemiol 2009;19:231-234. (C) 2009 Elsevier Inc. All rights reserved.