It is usually believed that the probability of hepatitis B infection is not directly related to age, and that the probability of infection is relatively lower if the immune mechanism is well developed or if one has already received the hepatitis B vaccine. Hepatitis B is a common type of viral hepatitis, which has a high incidence in China and can occur in people of all ages. If the autoimmune mechanism is well developed, when acute infection occurs, it can rely on the autoimmune mechanism to remove the hepatitis B virus and produce protective antibodies, reducing the probability of infection. In addition, with the soundness of the hepatitis B vaccination mechanism, the vast majority of people have been vaccinated against hepatitis B and have produced protective antibodies in their bodies, so the probability of hepatitis B infection will be greatly reduced. Therefore, the probability of hepatitis B infection is not directly related to age. If you are infected with hepatitis B virus, it is recommended that you consult a doctor in a timely manner, under the guidance of the doctor, complete the relevant examinations, identify the cause of the disease and treat the symptoms.