title: Immunogenicity of hepatitis B vaccine in preterm and full term infants vaccinated within the first week of life.
abstract: The immunogenicity of a Hepatitis B vaccine was evaluated in 110 neonates (57 full term and 53 preterm) born to Hepatitis B surface antigen (HBsAg) negative mothers. Three 10 microg doses of recombinant Hepatitis B vaccine were administered: the first dose within the first week of life; the second between 1 and 2 months; and the third at 5-7 months of age. Anti-HBs antibody titres were measured 3 months after the third dose. The seroconversion rate in preterm infants (77%; 95% CI=64.7-87.1) was significantly lower than in full term infants (98%; 95% CI=91.6-99.9) while the mean anti-HBs titres among those infants that did seroconvert was lower in preterm (186.6 mIU ml(-1)) than in full term infants (537.5 mIU ml(-1)). More full term than preterm infants showed titres greater than 100 mIU ml(-1) (71.9 and 41.5%, respectively). We conclude that the administration of a recombinant Hepatitis B vaccine shortly after birth is less immunogenic in preterm infants weighing <1800 g at birth than in full term infants. Currently accepted recommendations for post exposure perinatal prophylaxis may be inadequate to protect preterm infants.
authors.affiliation: Department of Pediatrics, School of Medicine of Ribeirão Preto, University of São Paulo, Av. dos Bandeirantes no. 3900, Ribeirão Preto, São Paulo, Brazil. marciasfmotta@hotmail.com
authors.forename: Márcia Soares
authors.initials: MS
authors.lastname: Freitas da Motta
authors.forename: Marisa Márcia
authors.initials: MM
authors.lastname: Mussi-Pinhata
authors.forename: Salim Moysés
authors.initials: SM
authors.lastname: Jorge
authors.forename: Clara Fumiko
authors.initials: CF
authors.lastname: Tachibana Yoshida
authors.forename: Cleonice Barbosa
authors.initials: CB
authors.lastname: Sandoval de Souza
mesh_terms: D005260:Female; D006509:Hepatitis B / Q000276:immunology / Q000517:prevention & control* / Q000635:transmission; D006510:Hepatitis B Antibodies / Q000097:blood; D006514:Hepatitis B Surface Antigens / Q000097:blood; D017325:Hepatitis B Vaccines / Q000008:administration & dosage* / Q000276:immunology; D006801:Humans; D007115:Immunization Schedule; D007223:Infant; D007231:Infant, Newborn / Q000276:immunology*; D007234:Infant, Premature / Q000276:immunology*; D018445:Infectious Disease Transmission, Vertical; D008297:Male; D014614:Vaccines, Synthetic / Q000008:administration & dosage* / Q000276:immunology
chemical_list: C075654:Engerix-B; D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines; D014614:Vaccines, Synthetic