Are booster immunisations needed for lifelong hepatitis B immunity?

Long-term protection against clinically significant breakthrough hepatitis B (HB) virus infection and chronic carriage depends on immunological memory , which allows a protective anamnestic antibody response to antigen challen ge. Memory seems to last for at least 15 years in immunocompetent individua ls. To date there are no data to support the need for booster doses of HE v accine in immunocompetent individuals who have responded to a primary cours e. All adequately vaccinated individuals have shown evidence of immunity in the form of persisting anti-Has and/or in vitro B-cell stimulation or an a namnestic response to a vaccine challenge. Nonetheless several countries an d individuals currently have a policy of administering booster doses to cer tain:risk groups. Boosters may be used to provide reassurance of protective immunity against benign breakthrough infection. For immunocompromised pati ents, regular testing for anti-HBs, and a booster injection when the titre falls below 10 mIU/mL, is advised. Long-term monitoring should continue, to confirm the absence of clinically significant breakthrough episodes of hep atitis B and to find out if a carrier state develops after 15 years. Also, non-responders to a primary course should continue to be studied.