The child’s hepatitis B antibody test of 40+ should be done as a quantitative test. 40+ between 10-100 indicates a relatively weak resistance to the hepatitis B virus, in which case a booster shot of hepatitis B vaccine should be given. Whether the hepatitis B vaccine has produced effective protection after vaccination depends on the level of antibodies, and generally if it is between 10 and 100, a booster shot is needed. If the antibody level is above 100, it usually indicates a relatively strong resistance to the hepatitis B virus and a booster vaccination is not needed for the time being. If it is less than 10, it usually indicates that there is no resistance to hepatitis B. Generally, three doses of hepatitis B vaccine should be given again.