Children with no antibodies to the hepatitis B vaccine need to be re-tested. If children have been vaccinated with hepatitis B vaccine, but there is no antibody in the body after checking, it refers to the disappearance of hepatitis B antibody in the body at present, and it is necessary to give the children hepatitis B vaccine again to make up the vaccine, so as to produce sufficient antibody in the body to resist the infection of hepatitis B virus, and the adults, if such a situation occurs, should also be vaccinated with hepatitis B vaccine. Hepatitis B vaccination is divided into 3 injections, according to the procedure of 0, 1 and 6. After the third injection, the positive rate of hepatitis B surface antibody in the body can be up to 96%, and it is necessary to go to the hospital for testing after the injection. In addition, the effect of hepatitis B vaccine after injection is not permanent, usually after a few years, you need to go to the hospital to test the hepatitis B surface antibody.