Generally speaking, hepatitis B surface antibody greater than 10mIU/mL is protective, but at this time it is weaker and less protective, so it is better to have a titer of hepatitis B surface antibody greater than 100mIU/mL, which is relatively more protective. In clinical work, it is recommended to review the five indicators of hepatitis B once every 3-5 years to observe the titer of hepatitis B surface antibody. If the titer of hepatitis B surface antibody is below 100mIU/mL, a booster shot of hepatitis B vaccine is recommended at this time. If the titer of hepatitis B surface antibody is less than 10mIU/mL, it is recommended to re-inject three doses of hepatitis B vaccine. The procedure for the three doses of hepatitis B vaccine is the 0-1-6 principle, and the five indicators of hepatitis B will be rechecked one month after the vaccination to see if the vaccination is successful and to observe whether the titer of hepatitis B surface antibody has risen.