Hepatitis B vaccination is necessary for adults, but it is not necessary if one is being infected with the hepatitis B virus or has been infected with the hepatitis B virus. Hepatitis B vaccine, an inactivated vaccine, protects against viral hepatitis B. This vaccination stimulates the body to produce protective antibodies, which gives the body the ability to fight off the hepatitis B virus, thus preventing the emergence of hepatitis B. The hepatitis B virus is contagious, so it is important for adults to be vaccinated against it. Since hepatitis B is contagious, vaccination against hepatitis B is necessary for adults, especially those with high-risk factors, such as medical personnel, immunocompromised people, organ transplant recipients, and people who often need to come into contact with blood. And high-risk groups need to regularly check the body’s hepatitis B surface antibody titer, titer is not enough to fight against the hepatitis B virus, but also need to be supplemented with vaccine to strengthen the immunization. However, before adults receive the hepatitis B vaccine, they should first check the hepatitis B two half, if they are infected with the hepatitis B virus, it is not necessary to receive the vaccine. If you have been infected with Hepatitis B virus before and your antibody titer is high enough, there is no need to receive Hepatitis B vaccine. Individuals should have knowledge and understanding of Hepatitis B and need to recognize the need for Hepatitis B vaccination to maintain their health.