title: Response to the complete hepatitis B vaccine regimen in infants under 12 months of age: a case series.
abstract: OBJECTIVE
  Describing rates of seroconversion and its associated factors in a series of Brazilian infants following the final dose of the vaccine at 6 months of age.
  
  
  METHODS
  Peripheral blood samples were collected after the third dose of the vaccine for the detection of anti-hepatitis B surface antibodies among infants of 7-12 months of age. We measured the association between seroconversion and birthweight, gestational age, time since administration of the vaccine in the maternity hospital and whether or not testing for hepatitis B surface antigen had been performed during pregnancy.
  
  
  RESULTS
  We examined 40 infants. The mean birthweight was 2787g (standard deviation=853g) and mean gestational age was 37.5 (standard deviation=3.08) weeks. The proportion that seroconverted was non-significantly higher in infants who weighed ≥2000g at birth (96.7%) than in those with birthweights <2000g (80%, p=0.149). There was no difference between the infants who were born at <37 weeks of gestational age and those born at ≥37 weeks (p<0.178) neither between seroconversion and the time of application of the first dose of the vaccine after delivery (p=0.202).
  
  
  CONCLUSIONS
  The proportion of infants who seroconverted was similar to that found in other Brazilian studies. There were no differences in the proportion seroconverting by age at first immunization.
authors.affiliation: Universidade do Estado do Amazonas, Amazonas Foundation of Tropical Medicine, Manaus, AM, Brazil. alexmiralha@hotmail.com
authors.forename: Alexandre Lopes
authors.initials: AL
authors.lastname: Miralha
authors.forename: Adriana
authors.initials: A
authors.lastname: Malheiro
authors.forename: Angélica Espinosa
authors.initials: AE
authors.lastname: Miranda
authors.forename: George Williams
authors.initials: GW
authors.lastname: Rutherford
authors.forename: Maria das Graças Costa
authors.initials: Md
authors.lastname: Alecrim
mesh_terms: D001938:Brazil; D005260:Female; D006509:Hepatitis B / Q000276:immunology / Q000517:prevention & control*; D006510:Hepatitis B Antibodies / Q000097:blood* / Q000276:immunology; D006514:Hepatitis B Surface Antigens / Q000097:blood* / Q000276:immunology; D017325:Hepatitis B Vaccines / Q000008:administration & dosage / Q000276:immunology*; D006515:Hepatitis B virus / Q000276:immunology*; D006801:Humans; D007115:Immunization Schedule; D007223:Infant; D007230:Infant, Low Birth Weight / Q000276:immunology; D007231:Infant, Newborn; D007234:Infant, Premature / Q000276:immunology; D008297:Male
chemical_list: D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines