Low-dose intradermal administration of recombinant hepatitis B vaccine in children: 5-year follow-up study.
Several studies have documented the efficacy of low-dose intradermal administration of hepatitis B vaccine. However, little is known about the duration of protection provided by low-dose intradermal administration of hepatitis B vaccine. This study reports results from a 5-year follow up period of 200 healthy children (100 infants and 100 preschool children) immunized intradermally with 2 microg doses of recombinant hepatitis B vaccine (GenHevac B) at months 0,1, and 6. In the 8th week after the third vaccine dose, 97% of the children developed anti-HBs antibodies higher than or equal to 10 mlU ml(-1), and the antiHBs geometric mean titre (GMT) was 676 mlU ml(-1). In month 18 and year 5, the anti-HBs GMT decreased to approximately one-third (220 mlU ml(-1)) and one-tenth (68 mlU ml(-1)) of the initial levels, respectively. However, 87% of the children had protective levels of anti-HBs (> or =10 mlU ml(-1)) after 5 years. Among 156 children followed for 5 years, none became positive for anti-HBc and/or HbsAg. Seven children who were seronegative after 5 years developed anti-HBs antibodies higher than 1000 mlU ml(-1) after an additional 10 microg intramuscular hepatitis B vaccine. Persistent immunologic memory over periods of 5 years or more is evident, the anamnestic antibody response to a booster dose of vaccine, even in these children who have lost antibody. We conclude that intradermal administration of 2 microg recombinant hepatitis B vaccine provides long-term protection against hepatitis B virus in infants and preschool children.
Kurugöl
Z
Z
Department of Pediatrics, Ege University Faculty of Medicine, Izmir, Turkey. kurugol@med.ege.edu.tr
Erensoy
S
S
Akşit
S
S
Egemen
A
A
Bilgiç
A
A
D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006510:Hepatitis B Antibodies / Q000097:blood; D017325:Hepatitis B Vaccines / Q000008:administration & dosage*; D006801:Humans; D007115:Immunization Schedule; D007117:Immunization, Secondary; D007156:Immunologic Memory; D007223:Infant; D007271:Injections, Intradermal; D008297:Male; D013997:Time Factors; D014421:Turkey; D014614:Vaccines, Synthetic / Q000008:administration & dosage
C075656:GenHevac B Pasteur; D006510:Hepatitis B Antibodies; D017325:Hepatitis B Vaccines; D014614:Vaccines, Synthetic