According to CDC guidance the hepatitis b vaccine series does not need to be restarted, no matter how long ago the previous dose was given. It states to give the 2nd dose now, and then the 3rd dose 2-6 months later. Also, a titer should only be done 1-2 months after completing the series. When done at longer intervals it is not accurate. The hepatitis b vaccine has an long-term immunologic memory & when the person is exposed antibodies are produced. If a titer >10 is documented the person is always considered immune. If there is no documented titer you should only get one if the employee is exposed . There is a really good information brochure available on the Immunization Action Coalition's website
www.immunize.org. Type in "Hepatitis B and the Health Care Worker" in the search field and you will get the info sheet. It answers lots of questions about Hep B vaccine for occ health people. I keep them in the Employee Health office to pass out to explain the hep b series.