The hepatitis B vaccine is the best way to prevent infection. It is a series of 3 or 4 shots usually given over a 6-to-12 month period. It is given by an injection into the arm muscle of adolescents and adults and thigh muscle of infants and young children.cute (short-term) illness, the symptoms of which are flu-like. Most adults who get hepatitis B have this acute form of hepatitis B, and then get better. Chronic (long-term) infection which can be very serious, and often leads to liver damage, liver cancer, or death.