Post-90s usually have been injected with hepatitis B vaccine, and the hepatitis B vaccination program for post-90s is also more standardized. Hepatitis B vaccine is mainly used to prevent the occurrence of hepatitis B. After injecting the vaccine, the body can be stimulated to produce hepatitis B surface antibodies, and after the surface antibodies are produced, the occurrence of viral hepatitis B will be prevented and hepatitis B will be prevented. Clinically, the general immunization procedure is according to 0, 1, 6 for injection, injection of three doses. People born after 90, have been strictly in accordance with the above procedures for hepatitis B. Vaccines generally require timely injection of the first injection of hepatitis B vaccine and BCG vaccination within 24 hours after birth. The injection may be delayed in patients with allergies, jaundice, prematurity, severe organ malformations, and fever. Most infants and children will not have obvious adverse reactions after injection, a few patients may have fever, abdominal pain, diarrhea, loss of appetite, redness and swelling at the site of vaccination, etc., but they will gradually disappear within three days. For patients who received hepatitis B vaccine after 90 days, it is also necessary to review hepatitis B 5 regularly to determine whether there is a weakening of hepatitis B surface antibody, and if necessary, need to strengthen the injection. If there is any discomfort, you should consult a doctor in time.