Hepatitis B is very dangerous, it is contagious and may be passed on to the next generation, and some patients may develop cirrhosis or liver cancer and die. Therefore, it is important to prevent hepatitis B. One of the most direct and effective ways to prevent hepatitis B is to get the hepatitis B vaccine. The hepatitis B vaccine will activate the body’s immune system and produce hepatitis B surface antibodies, which will ensure that the body is immune to the hepatitis B virus and prevent infection with it, but will continue to lower the immune capacity over time. Hepatologists remind us that the hepatitis B vaccine does not guarantee a lifetime of freedom from infection. It is recommended that a quantitative examination be performed in one to three years to see if it is necessary to continue the vaccination. In fact, how often the hepatitis B vaccine is given depends on whether it is for adults, or young children. In the case of a newborn baby, the hepatitis B vaccine is usually given once within 24 hours of birth, and then one month later, and then one after 6 months, for a total of 3 shots, so the parents of the child need to pay attention to this aspect. As for adults, after the hepatitis B vaccination, generally speaking, the effective protection time is about ten years, but it varies from person to person, because everyone’s immunity is different, if it is a high-risk group after the vaccination, then in about ten years, it is better to monitor again.