title: Effect of a diphtheria booster vaccination in adults with a documented history of an incomplete primary series vaccination.
abstract: BACKGROUND
  An incomplete series of diphtheria vaccination is frequently found in the vaccination documents of adult patients. This paper investigates the effect of a booster vaccination in adults with an incomplete series of primary vaccination.
  
  
  METHODS
  The effect of one diphtheria booster vaccination in adults with a documented history of only two childhood vaccinations has been investigated in 21 adults. Before the vaccination and 4 to 8 weeks thereafter, blood samples were taken and analyzed with an in vitro neutralization assay.
  
  
  RESULTS
  None of the participants had prevaccinal full protective diphtheria antitoxin levels (AT) > or = 0.1 IU/ml and four (19%) had limited serological protection (AT 0.01 to 0.1 IU/ml). After the vaccination, 14 individuals (67%) had protective LeveLs and six (29%) had limited protective levels. The risk for post-booster non-protection (AT < 0.1 IU/ml) was 7.7 times higher in comparison with a group of 170 adults with a history of at least one booster vaccination.
  
  
  CONCLUSIONS
  A specific immunologic memory exists in adults with a history of only two previous diphtheria vaccinations. However, our results also indicate the need for a second booster vaccination in this group if long-term protection is to be achieved.
authors.affiliation: Dept. of Occupational Medicine, University of Wuppertal, Wuppertal, Germany. hasselho@uni-wuppertal.de
authors.forename: H M
authors.initials: HM
authors.lastname: Hasselhorn
authors.forename: F
authors.initials: F
authors.lastname: Hofmann
authors.forename: M
authors.initials: M
authors.lastname: Nübling
mesh_terms: D000328:Adult; D004166:Diphtheria Antitoxin / Q000097:blood / Q000276:immunology; D004168:Diphtheria Toxoid / Q000008:administration & dosage* / Q000276:immunology*; D005260:Female; D006801:Humans; D007115:Immunization Schedule; D007117:Immunization, Secondary; D007156:Immunologic Memory / Q000276:immunology; D008297:Male; D008875:Middle Aged
chemical_list: D004166:Diphtheria Antitoxin; D004168:Diphtheria Toxoid