Like Hepatitis C, Hepatitis B is a viral disease that affects the liver. It is transmitted by exposure to infected blood or body fluids such as semen and vaginal fluids. Viral DNA has also been found in the saliva, tears, and urine of chronic carriers. The first vaccines for Hep B were being tested by the early 1980s and it became a commercially available vaccine in the USA in 1982.  By the mid-1990s, Brazil introduced the Hepatitis B vaccination within its national immunization system.