How often should the hepatitis B vaccine be administered?

The hepatitis B vaccine typically requires three doses administered on a 0-1-6 month schedule, meaning the second dose is given one month after the initial dose, and the third dose is administered six months after the initial dose. After completing the vaccination series, most people will develop hepatitis B surface antibodies, although the duration of these antibodies varies among individuals. It is recommended to regularly monitor hepatitis B surface antibody titers, and a booster dose may be considered if antibody levels decline. For catch-up vaccination in adults and children who missed the routine vaccination schedule, the remaining doses should be completed as soon as possible. If an individual has already completed the primary three-dose series but requires enhanced immunity for certain reasons, it is generally recommended to check antibody titers every 5–10 years after completing the primary vaccination series. A booster dose should be administered if hepatitis B surface antibody levels are found to be low. The vaccination schedule may differ for high-risk groups or individuals with weakened immune systems.