Q: I am 29 years old and have taken two shots of hepatitis B vaccine and I was asked to take another one early this year, which I missed. I would like to know if I have to now only take the last shot or do I have to start all over again?

A:No you needn't repeat all the doses, but only take the last (missed) shot and this will suffice. Please get the protective antibody (antibody to the Hepatitis B surface antigen) level tested after a period of 1.5 months to ensure protection.