Antibody levels in Ethiopian children five years after vaccination with two different doses of hepatitis B vaccine: is there a need for booster vaccine?
It was hypothesized that, following effective initial vaccination, a booster dose of hepatitis B vaccine will not be necessary in areas of hyperendemicity for hepatitis B virus (HBV) infection. A total of 314 Ethiopian children, ranging from two to 14 years old, were alternatively vaccinated with 10 and 20 micrograms hepatitis B vaccine doses, using the initial, one- and six-month schedule. Five years later, 210 of the vaccinees were retested for anti-HBV surface antibody titres. Both 10 and 20 micrograms doses of hepatitis B rDNA yeast vaccine were equally immunogenic and protective against HBV infection for at least five years despite marked reduction of mean antibody levels and geometric mean titres, with 11% of the vaccinees showing antibodies below the protective level. For firm further recommendations a longer follow-up period of vaccinees is suggested.
Tsega
E
E
Department of Internal Medicine, Faculty of Medicine, Memorial University, St John's, Newfoundland. lestsega@nf.sympatico.ca
Horton
J
J
Nordenfelt
E
E
Hansson
B J
BJ
Tafesse
B
B
Wolde-Hawariat
G
G
Lindberg
J
J
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005002:Ethiopia; D005260:Female; D006509:Hepatitis B / Q000276:immunology* / Q000517:prevention & control*; D006510:Hepatitis B Antibodies / Q000097:blood*; D017325:Hepatitis B Vaccines / Q000008:administration & dosage*; D006801:Humans; D007117:Immunization, Secondary; D008297:Male; D013997:Time Factors
D006510:Hepatitis B Antibodies; D017325:Hepatitis B Vaccines