Many parents think that everything will be fine after vaccination, and their children will definitely not be infected with vaccine-prevented diseases, which is actually not the case. CDC experts explained that a variety of vaccines have a certain rate of protection, due to individual differences in vaccine recipients, a small number of people do not produce a protective effect after vaccination, there may still be a disease. In addition, if the vaccination recipient happens to be in the incubation period of the disease targeted by the vaccine, the vaccine has not yet produced a protective effect after vaccination, so the vaccination may be coupled with the onset of disease. Hepatitis B vaccination is currently an effective preventive measure against hepatitis B. However, many factors can influence hepatitis B vaccination. However, many factors can affect the preventive effect of hepatitis B vaccine, so it should not be taken lightly. For example: 1, passive smoking: the relevant survey found that the antibody level in children with passive smoking decreases faster; 2, obesity; 3, picky eaters: picky eaters often have certain nutritional deficiencies, so that the body’s immune response function is reduced, and the body produces limited antibodies, and thus susceptible to hepatitis B virus infection. Vaccine dosage has a certain influence on the vaccination effect. It has been found that the production of hepatitis B surface antibodies after vaccination is also related to many factors such as the immune status, gender, age, race and nutritional status of the vaccinated person. (1) Infants have a stronger and more rapid ability to produce antibodies and protective effects to the vaccine than adults. (2) Young people have better vaccination results than the elderly. (3) The rate of hepatitis B surface antibody conversion is higher in women than in men after vaccination with the same dose and under the same conditions. (4) The ability of the body with immunodeficiency to respond to hepatitis B vaccine is significantly reduced. After hepatitis B vaccination, the higher the titer of hepatitis B surface antibody is, the longer the antibody persists, and the protection ability is correspondingly longer. Introduce the child’s disease history before vaccination When vaccinating the child, parents must pay attention to the following details: 1. Parents should take the child to the vaccination unit such as health epidemic prevention station, community health service station or liver disease hospital for vaccination; 2. Parents should provide the child’s physical health condition, including the history of disease, allergy and whether fever, diarrhea and other details; 3. After vaccination, the child should take a rest for 30 minutes at the vaccination site; 4. 4. Parents should not give their children a bath on the day of vaccination, keep the skin of the vaccination site clean, and should not scratch it with their hands; avoid spicy and greasy food, and should eat more light and easy-to-digest food. A small number of children will have a general reaction after vaccination, and individual children will have an abnormal reaction. Those who have serious symptoms of general reaction and those who have an abnormal reaction should seek medical treatment in time and inform the preventive vaccination unit of the reaction, and consult the doctor of the unit for details. General reaction to preventive vaccination refers to the occurrence after preventive vaccination, caused by the inherent characteristics of the vaccine itself, mainly fever and local redness and swelling, which may be accompanied by a combination of symptoms such as general malaise, lethargy, loss of appetite, and fatigue. The reaction lasts for about 1 to 2 days and usually resolves on its own.