Booster doses of hepatitis B vaccine: responses to low-dose inoculations.
OBJECTIVE
To examine the anamnestic response to hepatitis B vaccine in previously vaccinated subjects.


METHODS
Subjects who had received a course of hepatitis B vaccine at least two years previously had a sample of blood taken before and seven days after a low-dose booster of hepatitis B vaccine.


METHODS
A pilot group of laboratory scientists in the Microbiological Diagnostic Unit; fifth year medical students, University of Melbourne; and a group of ambulance officers from the Geelong Ambulance Depot (Victoria). All participants volunteered after having been informed of the study.


METHODS
Serum levels of antibody to hepatitis B surface antigen (HBsAg) were measured before and after the booster dose of vaccine and, when available, in serum taken a month after the end of the primary course of vaccine, and the changes in antibody level were studied.


RESULTS
Although some individuals with a restricted antibody response were identified, most showed a quick response. There was limited evidence that this rise peaked early and began to fall within weeks.


CONCLUSIONS
In many subjects, levels of antibody to HBsAg peak early after booster doses of vaccine but the rapid anamnestic response to small amounts of antigen make it probable that effective protection from symptomatic illness may be long lasting, when there has been a satisfactory primary response. This provides an argument for testing for adequate seroconversion after vaccination.
Thompson
S C
SC
Health and Community Services, Infectious Diseases Program, Melbourne, Vic.
Darlington
R
R
Tallent
D
D
Forsyth
J R
JR
D000328:Adult; D004634:Emergency Medical Technicians; D006510:Hepatitis B Antibodies / Q000032:analysis*; D006514:Hepatitis B Surface Antigens / Q000276:immunology; D017325:Hepatitis B Vaccines / Q000008:administration & dosage / Q000276:immunology*; D006801:Humans; D007117:Immunization, Secondary; D007231:Infant, Newborn; D017056:Medical Laboratory Personnel; D008875:Middle Aged; D010865:Pilot Projects; D013337:Students, Medical
D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines