Hepatitis B vaccine
Hepatitis B virus causes liver infection, which can become chronic and lead to liver failure or cancer. Illness includes vomiting, abdominal pain, fatigue, jaundice, and, rarely, death in the acute phase. Infection occurs through contaminated needles or syringes, contaminated blood products, and sexual contact. Three doses are given (at 0, 1, and 6 months). Accelerated schedules consist of 3 doses (0, 1, and 2 months; 0, 7, and 21 days; or 0, 7, and 14 days) plus a fourth dose at 12 months. A completed vaccine schedule provides lifelong immunity.