Hepatitis B surface antibody of 30IU/L can also be infected, but the relative risk of being infected by the hepatitis B virus is reduced. Hepatitis B surface antibody greater than 10IU/L means that the body has effective antibodies against the hepatitis B virus, and the higher the antibody value, the lower the risk of infection. Hepatitis B surface antibody of 30IU/L also carries the risk of infection, only that the risk of hepatitis B virus infection will be reduced compared to patients without hepatitis B surface antibody. The reference value for hepatitis B surface antibody is 10IU/L. If it is less than 10IU/L, then you do not have effective antibodies against the invasion of hepatitis B virus. If the hepatitis B surface antibody is greater than 10IU/L, it means that you have effective antibodies against the hepatitis B virus. The higher the value of Hepatitis B surface antibody, the lower the risk of the patient being infected by Hepatitis B virus. In addition to hepatitis B vaccination, generally during the recovery period of hepatitis B virus infected patients, patients may also have elevated hepatitis B surface antibody, which has been infected with hepatitis B virus, and can be differentiated from those who are positive due to vaccination by checking the hepatitis B two-half-pair test.