If you have already completed the full 3-dose Hepatitis B vaccine series about 10 years ago, you are very likely still protected, because long-term immunity usually persists even if antibody levels decrease over time. In most cases, repeating the Hepatitis B part of the vaccine is not necessary. The Twinrix vaccine contains both Hepatitis A and Hepatitis B components, so taking it again would mainly act as an extra booster for Hepatitis B, but it is usually not required if your previous vaccination was complete and effective. What is more important is to check whether you need protection against Hepatitis A, since many adults are not vaccinated for it in childhood. Instead of taking the full Twinrix course without assessment, a doctor may first suggest a simple blood test for Hepatitis B surface antibodies to confirm immunity, and then decide whether you only need the Hepatitis A vaccine alone or any booster. If Twinrix is still chosen, it is generally safe to take, but it may be unnecessary exposure to the Hepatitis B component. So overall, it is safe, but not routinely needed to repeat the full course, and the best approach is to tailor vaccination based on your current immunity status and risk.