After accidental exposure to blood or body fluids of a person infected with hepatitis B virus, the following methods can be followed to avoid infection with hepatitis B: 1. Serological testing HBsAg, anti-HBs, HBVDNA, anti-HBc, HBeAg, ALT and AST should be tested immediately and retested within 3 and 6 months. 2.Active and passive immunization Those who have been vaccinated against hepatitis B and have known anti-HBs ≥10 mIU/ml may be exempted from special treatment. Those who have not received hepatitis B vaccine, or have received hepatitis B vaccine but anti-HBs <10 mIU/ml or the level of anti-HBs is unknown, should immediately receive HBIG 200-400 IU and one dose of hepatitis B vaccine (20mg) at different sites at the same time, and the second and third doses of hepatitis B vaccine (20mg each) 1 and 6 months later respectively.