E. Tsega et al., ANTIBODY-LEVELS IN ETHIOPIAN CHILDREN 5 YEARS AFTER VACCINATION WITH 2 DIFFERENT DOSES OF HEPATITIS-B VACCINE - IS THERE A NEED FOR BOOSTERVACCINE, Canadian journal of gastroenterology, 12(1), 1998, pp. 57-60
It was hypothesized that, following effective initial vaccination, a b
ooster dose of hepatitis B vaccine will not be necessary in areas of h
yperendemicity for hepatitis B virus (HBV) infection. A total of 314 E
thiopian children, ranging from two to 14 years old, were alternativel
y vaccinated with 10 and 20 mu g hepatitis B vaccine doses, using the
initial, one-and six-month schedule. Five years later, 210 of the vacc
inees were retested for anti-HBV surface antibody titres. Both 10 and
20 mu g doses of hepatitis B rDNA yeast vaccine were equally immunogen
ic and protective against HBV infection for at least five years despit
e marked reduction of mean antibody levels and geometric mean titres,
with 11% of the vaccinees showing antibodies below the protective leve
l. For firm further recommendations a longer follow-up period of vacci
nees is suggested.