Progress in vaccination against hepatitis B in the Americas.

Hepatitis B is a serious public health problem leading to chronic infection, liver cirrhosis, and hepatocellular carcinoma. The World Health Organization (WHO) and the Pan American Health Organization (PAHO) recommend routine universal infant vaccination against hepatitis B as the main strategy for the control hepatitis B and its severe consequences. PAHO additionally recommends routinely vaccinating healthcare workers. As of 2005, all countries in the Americas, except Haiti and Dominica, have hepatitis B vaccine in their childhood immunization schedule; 13 countries/territories include a hepatitis B dose given at birth. Hepatitis B vaccine has been incorporated into national schedules using different modalities; notably, 28 countries use it as a combination vaccine diphtheria tetanus pertussis + Haemophilus influenzae type b + hepatitis B (DTP+Hib+Hep B) for infants. Coverage levels for the third dose of hepatitis B are usually over 80%; however, hepatitis B vaccine coverage overall is lower than for the third dose of DTP. Insufficient information is available at this time to assess the use of hepatitis B vaccine in healthcare workers in the Americas. The most important factor associated with the success in the implementation of hepatitis B vaccination has been the strong commitment of country governments. This experience can be used as a model when implementing new technologies in health as they become available. However, much still needs to be done to improve hepatitis B coverage.