Hepatitis B vaccine refers to recombinant hepatitis B vaccine, which is usually needed if the body does not have protective antibodies. The absence of protective antibodies usually means that when people go to the doctor for hepatitis B penta test, they find that hepatitis B surface antibody is negative. Hepatitis B surface antibody is a protective antibody, which can prevent the body from being infected by hepatitis B virus, thus reducing the chances of suffering from viral hepatitis B. Therefore, people who clearly have no protective antibodies should receive recombinant hepatitis B vaccine as soon as possible. Therefore, people who are clear that there is no protective antibody against hepatitis B in their body should seek medical advice as soon as possible for full vaccination with recombinant hepatitis B vaccine in order to prevent the disease. After receiving recombinant hepatitis B vaccine, some people may experience adverse reactions such as redness, swelling, pain, weakness and diarrhea at the injection site, which usually do not require treatment and can be relieved on their own. This vaccine is contraindicated in special groups such as those who are clearly allergic to the components of the recombinant hepatitis B vaccine, those who are in the febrile stage, those who are suffering from acute or chronic serious illnesses, and those who are pregnant. It is recommended that those who need it should receive recombinant hepatitis B vaccine in regular hospitals, and consult a doctor for examination after the whole vaccination process, in order to ascertain whether the surface antibody of hepatitis B is positive or whether the body has produced protective antibody.