Hepatitis B booster shots are usually given every three years and are not harmful in the long term. Hepatitis B booster shots can strengthen the effect of hepatitis B vaccine and effectively prevent hepatitis B virus infection. Since the antibodies produced by the vaccine cannot exist permanently in the body, and may gradually weaken or disappear with the extension of time, hepatitis B antibodies can usually be given once every three years to strengthen the number of hepatitis B antibodies in time and enhance the body’s preventive ability. Hepatitis B booster shot is mainly a genetic recombination vaccine, its active ingredient is hepatitis B surface antigen, that is, the shell of the hepatitis B virus, which is not infectious, and will not harm the liver and other parts of the human body tissues, so every three years to take hepatitis B booster shot for a long time is not harmful to the body. People who need to receive hepatitis B booster shots should do so under the guidance of a doctor and carefully read the precautions as well as contraindications.