Weak positive hepatitis B antibody is a qualitative test, and it is necessary to quantitatively test hepatitis B surface antibody through the hepatitis B penta test in order to determine whether to strengthen the hepatitis B vaccine. Hepatitis B surface antibody is the main basis for determining whether it is necessary to receive a booster shot of hepatitis B vaccine. Hepatitis B surface antibody titers between 10 and 100 IU/mL require a booster shot of hepatitis B vaccine. Hepatitis B surface antibody titer less than 10IU/mL is considered extremely low, and a full course of Hepatitis B vaccine is needed to stimulate the body to produce sufficient titers of protective Hepatitis B antibody. Before the booster injection of hepatitis B vaccine, it is necessary to do hepatitis B penta test to make sure that the body is not currently infected with hepatitis B virus, i.e. hepatitis B surface antigen negative.